13 Weeks Pregnant: Baby Development, Symptoms & Signs

Maybe your like

Sign UpSign Out

Getting Pregnant
Pregnancy
First Year
Toddler
Family
Baby Names
Registry
Baby Products
Community Groups
News

TopicsFertilityOvulationPreparing for PregnancyPreconception HealthInfertilitySee All Getting Pregnant TopicsRecommended Reading

What is Implantation Bleeding and When Does It Occur?Implantation bleeding can mimic period bleeding, but it could also mean that you're pregnant. Here’s how to tell whether spotting or light bleeding is a sign of pregnancy, your period or something else.

Ovulation Symptoms: 10 Signs of OvulationSigns of ovulation can include increased basal body temperature, mild cramps and more. Here's what to expect — and how to use this information to increase your chances of getting pregnant.

Does a Faint Line on a Pregnancy Test Mean You're Pregnant?Taking a home pregnancy test is always a nail-biter. How accurate the results are depend a lot on when you take it and what the lines in the window reveal.

When Does Implantation Occur?Learn more about the possible signs and symptoms of implantation during pregnancy, plus when and why it happens.

How to Have a Boy or a GirlOn team blue or pink? Find out if these ways to choose baby's sex really work and whether it's a good idea to try them.Tools

Ovulation Calculator

IVF Due Date CalculatorTopicsPregnancy Week-by-WeekPregnancy SymptomsLabor & DeliveryPreparing for BabyFetal DevelopmentScreenings & TestsBaby’s Zodiac SignBaby ShowersPregnancy ComplicationsSee All Pregnancy TopicsRecommended Reading

Early Signs of PregnancyIf you’re trying to get pregnant, here’s a timeline of the early signs of pregnancy to look for, including tender breasts, fatigue, nausea and bloating.

Managing Morning Sickness and Nausea During PregnancyHere are the symptoms and causes of morning sickness, plus what you can do to relieve it.

Signs of LaborNot sure how to know if you're in labor? Look for these clues that it's almost show time!

Changes or Decreases in Fetal MovementHave your baby's movements changed? Find out what's normal and when to call the doctor.

Signs You Are Having a Boy or GirlHere are some clues to whether you're having a boy or a girl that have research behind them.

Braxton Hicks Contractions and False LaborHow to tell the difference between these false labor signs and the real deal.Tools

Pregnancy Due Date Calculator

Conception Date Calculator

Pregnancy Weight Gain Calculator

Chinese Gender PredictorTopicsBaby Month-by-MonthPostpartum RecoveryNewbornsMilestonesBreastfeedingBottle-FeedingIntroducing SolidsBaby SleepVaccinesSleep SchedulesFeeding SchedulesSee All First Year TopicsRecommended Reading

When Do Baby Growth Spurts Happen?You're not imagining it! Find out what happens during baby’s growth spurts.

How to Help a Gassy BabyHere's why your baby may be gassy and infant-safe treatments for baby gas.

11 Reasons Your Baby Won't SleepSolutions to issues that may be keeping your baby from sleeping through the night.

Gripe Water for BabiesLearn about this herbal treatment for gassy, fussy infants and see if it's safe.

What is Sleep Regression?Here's when they happen, how long they last and what you can do to help baby sleep better.Tools

Baby Tracker

Birth Chart CalculatorTopicsToddler Month-by-MonthHealth and SafetyGrowth and DevelopmentFeeding Your ToddlerToddler SleepPotty TrainingActivities and PlayLearningSee All Toddler TopicsRecommended Reading

Why Is Your Toddler Waking Up Too Early and What Should You Do About It?Use these tips to adjust your early riser's sleep schedule.

How to Potty Train Your Toddler in Three DaysHeard about the 3-day potty training method? Here's how to make it work.

How to Handle Toddler Night TerrorsHere’s what these sleep episodes are and some easy ways to handle them in your child.

Why Toddlers Refuse to Eat and What to DoShe used to gobble up everything you put on her plate — but now your toddler who won’t eat.

What to Do if Your Toddler Refuses to PoopYou wait, but it's a no-go. What to do if your toddler has trouble pooping on the potty.TopicsAdoptionFamily FinancesSecond Time ParentsChildproofingMental Health in ChildrenCar SafetyTraveling With KidsRelationshipsFamily ChangesRecipesSee All Family TopicsRecommended Reading

What is the Best Age Gap Between Kids?While there’s no "ideal" age gap between children, there are things to think about.

10 Best Second Pregnancy Announcements to Celebrate Baby Number Two (or Three!)Big feelings and big siblings!

Where to Find Financial Help as a Single MomThese services provide financial aid to low- and middle-income single mothers.

Do Babies Need Passports?Everything you need to know in order to get a U.S. passport for a baby.

When Is the Best Time to Have Your Baby Shower?There's no right or wrong time to celebrate your new arrival.TopicsTop Baby Names for BoysTop Baby Names for GirlsBest Gender-Neutral NamesUncommon Baby NamesUnique Girl NamesUnique Boy NamesSee All Baby Names TopicsRecommended Reading

Top Baby Boy Names That Start With ASee the most popular baby boy names that start with the letter A.

Top Baby Girl Names That Start With JSee the most popular baby girl names that start with the letter J.

Top Baby Girl Names That Start With MSee the most popular baby girl names that start with the letter M.

Top Baby Girl Names That Start With SSee the most popular baby girl names that start with the letter S.

Top Baby Boy Names That Start With KSee the most popular baby boy names that start with the letter K.TopicsRegistry ChecklistMy RegistriesRegistry 101See All RegistryTopicsAmazon Prime DayCar SeatsMaternity ClothesNursing & FeedingDiaperingBaby MonitorsBaby CarriersBaby CareNurseryToysStrollersSee All Baby ProductsRecommended Reading

Best Baby CarriersDeciding to use a baby carrier is the easy part. Deciding which type of carrier you’ll be wearing requires a little more research.

Best Baby MonitorsFind the perfect video baby monitor, recommended by parents who've tried them.

Best Diaper BagsDiaper bags keep you organized when you're on the go with baby. Check out the best diaper bags here.

Best Baby DealsWe scoured the web for the best markdowns on brands that What to Expect parents love.

Best Car SeatsInfant car seats are essential — you won't be able to leave the hospital without a rear-facing baby car seatTools

First Trimester Must-Haves

Second Trimester Must-Haves

Third Trimester Must-HavesTopicsFeatured & PopularBirth Month GroupsGetting PregnantPregnancyFirst YearFamilyHealthStagesInternationalUnited StatesAll Groups A-ZSee All Community Groups

Sign UpSign Out

Getting PregnantRECOMMENDED READINGTOOLSPregnancyRECOMMENDED READINGTOOLSFirst YearRECOMMENDED READINGTOOLSToddlerRECOMMENDED READINGFamilyRECOMMENDED READINGBaby NamesRECOMMENDED READINGRegistryBaby ProductsRECOMMENDED READINGTOOLSCommunity GroupsNewsPregnancy > Week by Week13 Weeks PregnantYour baby is as big as a lemon.previous item next item

3 in, 1 oz7.6 cm, 28 g

27Weeks to go!

by Catherine Donaldson-Evans reviewed mark

Medically Reviewed by Jennifer Wu, M.D., F.A.C.O.G.

All What to Expect content that addresses health or safety is medically reviewed by a team of vetted health professionals. Our Medical Review Board includes OB/GYNs, pediatricians, infectious disease specialists, doulas, lactation counselors, endocrinologists, fertility specialists and more.

We believe you should always know the source of the information you're reading. Learn more about our editorial and medical review policies. | July 29, 2025 Latest update: See more Explore Pregnancy Week 13

Baby development
Body changes
Common symptoms
Tips for you
Recommended products
Birth month group discussions

At 13 weeks pregnant, you're in the final week of your first trimester. (Can you believe you're already a third of the way through your pregnancy?!)

If you're like many parents-to-be, you may begin to tell people you're pregnant around week 13, but it's up to you when to give friends and family the news that baby is on the way.

Your Baby at Week 13

At a Glance

Eyes wide shutWhile baby’s eyes have arrived, they’re not open. His eyelids are fused shut to protect those tiny peepers as they continue to develop.

The voiceThe promise of laughter, cries, and very first words start now with the formation of vocal cords.

Balancing outThat big baby head is getting more in balance with the rest of the body. Right now, his head is about half the size of his total frame.

13 weeks pregnant is how many months?

If you're 13 weeks pregnant, you're in month 3 of your pregnancy. Only 6 months left to go! Still have questions? Here's some more information on how weeks, months, and trimesters are broken down in pregnancy.

How big is my baby at 13 weeks?

Besides being as large as a lemon now, that head of his is now about half the size of his crown-to-rump length. That's one reason why your little one looks more like an alien from outer space at this point. By the time you give birth, his body will catch up, measuring three-quarters of his total size.

But don't compare your fetus with the fetus next door. Starting in the next week or so, babies begin growing at different paces, some faster than others, some more slowly, though they all follow the same developmental path.

Baby's intestines and vocal cords are developing

What else is going on in there? At 13 weeks pregnant, tiny bones are beginning to form in his arms and legs. Because he can move them in a jerky fashion, he may be able to get his thumb into his mouth soon — a habit that may come in handy for self-soothing when he's a newborn.

Your baby's intestines are also in for some big changes. Until recently, they've been growing in a cavity inside the umbilical cord, but they've just moved into their permanent — and more conveniently located — address, in your baby's abdomen. And to serve your growing fetus' needs, the placenta is also growing, eventually weighing 1 to 2 pounds at birth.

Also developing this week: your baby's vocal cords (the first step toward saying, "I love you, Mommy!"). You obviously can't hear him crying or cooing just yet, but you can bet that little voice will get a good workout once he's born.

Your Body at Week 13

Feeling more like yourself?

Now that you're 13 weeks pregnant and just a week away from the second trimester, you should be feeling better soon. After all, the second trimester doesn't get its reputation for being the easiest and most comfortable of the three for nothing.

But if you are still struggling, don't worry. While most early pregnancy symptoms will probably be behind you soon, some women find that nausea and fatigue linger into the fourth and even fifth months.

And unfortunately for some women, those and other usual first trimester suspects — such as bloating, constipation, headaches, and breast tenderness — can continue to some extent throughout pregnancy.

Vaginal discharge

Of course, even though the second trimester is known as the trimester of smooth sailing, it doesn't mean you'll be symptom-free in the near future — far from it.

Something else you might have noticed recently is an increase in your vaginal discharge. Known as leukorrhea (try getting that right in a spelling bee), this perfectly normal discharge is thin and milky in color, and mild-smelling or sometimes even odorless. It will probably increase as your pregnancy progresses.

Leukorrhea is caused by the stepped-up production of estrogen as well as the increased blood flow to the pelvic area. Its purpose is noble: to protect the birth canal from infection and maintain a healthy balance of bacteria in the vagina. Unfortunately, in achieving its lofty goal, leukorrhea can make a mess of your underwear.

If it makes you more comfortable, use a panty liner, never a tampon, to stay dry. But never douche while you're pregnant, which can upset the normal balance of microorganisms, lead to vaginal infections, and even force air into the vagina during pregnancy, which can be harmful.

Sex during pregnancy

With all the extra discharge down there plus your burgeoning belly, you may be wondering whether your feelings about jumping into bed are normal. Try to go with the flow: When it comes to pregnancy sex, anything goes.

You may not be in the mood at all or you may be up for sex a lot more than usual. All of it is normal and likely to continue fluctuating as your pregnancy progresses.

Having twins?

Your belly's already bursting out of the seams of your largest jeans and you're just finishing up the first trimester. Could you be having twins? Maybe — especially if you have a history of fraternal twins in your family or you're over 35 (or both).

But there are other more likely explanations for your seemingly larger-than-life belly. For instance, it could be that your due date's off and your bigger-than-expected tummy is the result of a bigger-than-expected baby.

Or it could be that you're just full of it — gas, that is. Bloating can make a pregnant abdomen distend well beyond its weeks. It's also possible that you're taking the eating-for-two mandate a little too literally — say, you took everything you ate before you became pregnant and doubled it, leading to your early midsection expansion.

To find out what's really going on in there, check with your practitioner at your next visit. Who knows — you just might have two buns in your oven after all. You can't tell from the outside, no matter what your grandmother says!

Pregnancy Symptoms Week 13

Constipation Thanks to your hormones, your bowel muscles also relax during pregnancy, which means they'll be less efficient at moving waste out of your system. If you find yourself backed up, slowly start adding more high-fiber foods to your diet, like fruits, vegetables, and whole grains, along with plenty of fluids too. Read More

Food cravings and aversions If you still have a thing for weird foods, don’t be too hard on yourself. Do your best to find healthy foods that appeal to you and give yourself permission to indulge in small portions of the junk foods you crave. Read More

Heartburn and indigestion During pregnancy, the ring of muscle at the top of the stomach relaxes, allowing digestive acids to rise up into the esophagus — causing a burning in the chest. Reduce the pain by staying away from these possible heartburn triggers: alcohol, caffeinated drinks, chocolate, mint, citrus, and spicy or fatty foods. Read More

Faintness or dizziness Still plagued by dizzy spells? Don’t get up from a sitting or prone position too quickly, since it can trigger light-headedness. In the event that you do start to feel faint, immediately lie down or sit with your head between your knees. Read More

Visible veins Though you may not find these veins a welcome sight, they’re actually a good thing — your increased blood supply is carrying much-needed nutrients to your baby. Even more good news: The vein network fades after you give birth. Read More

Decreasing fatigue Now that your body has had a trimester to adjust to pregnancy, you may be starting to feel a little less tired these days. Consider channeling your newfound energy into your workout routine — but don’t overdo it! Read MoreTrack your symptoms with the My Journal tool in our free app

Tips for You This Week

Embrace your sex drive

Your second trimester is around the corner, and with it may come a boost in sex drive. Enjoy! What’s more, that spike in libido might have some health benefits for you and baby, since pregnancy sex can speed up postpartum recovery by tightening your pelvic floor muscles and improving your sleep and mood.

Not every woman will experience a super-sized sex drive (or any marked sex changes by trimester), however. So if your libido is lagging, don’t sweat it.

If you have a history of preterm labor or miscarriage, you may need to abstain from sex during pregnancy (also known as pelvic rest). Talk to your doctor about what you're safely able to do.Track your pregnancy symptoms

Now that you’re in your second trimester, you’re probably feeling a little bit better. Morning sickness may be (thankfully) behind you, and your energy levels have likely picked up.

Still, a whole new set of pregnancy symptoms can pop up for the first time — including congestion, mild swelling, and varicose veins. Track your symptoms to learn more about your ever-changing body and what’s going on in there. Find pregnancy-safe food at restaurants

You may not always get the chance to choose the restaurant, but now that you’re pregnant, it’s time to seize the opportunity.

If you're craving Italian, dine on grilled fish, chicken, veal, or lean-beef entrees accompanied by gorgeous greens. If it’s Japanese food you want, enjoy teriyaki fish or chicken, miso soup, edamame, and soba-noodle dishes.

And as long as your stomach's amenable to the spices in the cooking, Indian restaurants are another yummy, nutritious option — with plenty on the menu you can eat.

Don’t be shy about asking for substitutions if you need or want them. After all, you’re pregnant — so it’s especially important that what you eat is safe, healthy, and appetizing.Get used to the urine test

There’s one thing you can count on at every prenatal visit: the urine test. By taking a sample of your urine, your practitioner can test for some of the more common complications that can happen during pregnancy, including gestational diabetes, preeclampsia, and urinary tract infections.

For the most accurate results, start by washing your hands and wiping from front to back (your doctor will probably give you a wipe to use). Once you start peeing, catch the urine midstream with the collection cup. You’ll need about 1 to 2 ounces, so you may want to drink a glass of water before each visit.Keep track of skin changes

It’s not unusual for moles to develop or change right about now, thanks to pregnancy hormones.

But it’s still a smart move to have them evaluated by your doctor. Always check in with your practitioner about any skin changes you notice, just to be safe.Go for cotton underwear

An increase in vaginal discharge — known in medical-speak as leukorrhea — is often one of the first signs of pregnancy. It's also usually here to stay while you’re expecting, and the amount will likely increase as your pregnancy progresses.

Not to worry — this thin, white discharge is perfectly normal and healthy. Just keep the area clean and dry by bathing regularly and wearing breathable cotton underwear. If you're concerned about what you're seeing, call your doctor.Eat iron-rich foods

When you're making a baby, you're in the blood-making business — big-time. Since iron helps generate blood supply, it's a nutrient you'll need plenty of to keep your body's and your baby's supply of red in the black.

Up your intake of this vital mineral by eating such iron-rich foods as beef, duck, soy products, spinach, dried fruits, and potatoes with the skins on.

Your practitioner may also suggest a supplement after week 20 to keep your iron levels high enough as blood demand steps up. Just don’t take anything without your doctor’s approval. Medical Reviewed Reviewed July 29, 2025

From the What to Expect editorial team and Heidi Murkoff, author of What to Expect When You're Expecting. What to Expect follows strict reporting guidelines and uses only credible sources, such as peer-reviewed studies, academic research institutions and highly respected health organizations. Learn how we keep our content accurate and up-to-date by reading our medical review and editorial policy.View Sources

What to Expect When You're Expecting, 5th edition, Heidi Murkoff.
WhatToExpect.com, How Much Iron Do You Need During Pregnancy?, June 2022.
WhatToExpect.com, Do Twins Really Run in Families?, December 2021
Akron Children’s Hospital, Confessions of Prenatal Ultrasound Techs, February 2022.
Oxford University Press, Lachman's Case Studies in Anatomy, February 2013.
KidsHealth From Nemours, Week 12, April 2022.
Mayo Clinic, Fetal Development: The 1st Trimester, June 2022.
National Institutes of Health, National Library of Medicine, The Fetal Larynx and Pharynx: Structure and Development on Two- and Three-Dimensional Ultrasound, August 2013.
American College of Obstetricians and Gynecologists, Vulvovaginal Health, January 2022.
American College of Obstetricians and Gynecologists, Multiple Pregnancy, January 2023.
Cleveland Clinic, Acid Reflux & GERD, October 2023.
KidsHealth From Nemours, How Can I Deal with Heartburn During Pregnancy?, August 2019.
UpToDate, Placenta Previa: Management, October 2023.
National Institutes of Health, National Library of Medicine, Sex in Pregnancy, April 2011.
National Institutes of Health, Office of Dietary Supplements, Folate, November 2022.
Centers for Disease Control and Prevention, Folic Acid, June 2022.
Centers for Disease Control and Prevention, Show Me the Science – Why Wash Your Hands?, May 2023.
National Institutes of Health, National Library of Medicine, Calcium in Diet, January 2023.
National Institutes of Health, Office of Dietary Supplements, Iron, June 2023.
Academy of Nutrition and Dietetics, Easy Ways to Boost Fiber in Your Daily Diet, March 2021.
WhatToExpect.com, Vaginal Discharge During Pregnancy (Leukorrhea), January 2022.
WhatToExpect.com, Best Maternity Underwear, According to Moms-to-Be Who Tried Them, December 2021.
WhatToExpect.com, Skin Changes During Pregnancy, November 2022.
WhatToExpect.com, Urine Tests During Pregnancy, December 2022.
WhatToExpect.com, How to Safely Eat at Restaurants During Pregnancy, June 2022.
WhatToExpect.com, Sex Drive Changes During Pregnancy, July 2022.
WhatToExpect.com, When to Tell People You're Pregnant, June 2021.
WhatToExpect.com, How Many Weeks, Months and Trimesters in a Pregnancy?, May 2022.
WhatToExpect.com, What Is the Placenta? What This Organ Does and How It Forms, July 2021.
WhatToExpect.com, Pregnancy Symptoms: 14 Early Signs of Pregnancy, May 2023.
WhatToExpect.com, Are There Signs You're Pregnant With Twins?, December 2021.
WhatToExpect.com, Pregnancy Due Date Calculator and Conception Calculator, September 2023.
WhatToExpect.com, What to Do About Bloating During Pregnancy, February 2021.
WhatToExpect.com, Your Questions About Sex During Pregnancy, Answered, August 2021.
WhatToExpect.com, Heartburn During Pregnancy, October 2022.
WhatToExpect.com, Constipation During Pregnancy, October 2022.
WhatToExpect.com, Veiny Breasts During Pregnancy, April 2021.
WhatToExpect.com, Dizziness During Pregnancy, September 2022.

Recommended Products

What to Expect selects products based on real-life testing conducted by staff, contributors and members of our user community, as well as independent research and expert feedback; learn more about our review process. Prices and details are accurate as of the published date. We may earn commissions from shopping links.The 11 Best Pregnancy Pillows, Tested by 6 Tired Moms-to-Be View All Momcozy U-Shaped Pregnancy Pillow See Now Opens a new window

⚠️ You can't see this cool product because you have ad block enabled.

Please whitelist our site to get all the best deals and offers from our partners. ad block enabled Room Essentials Body Pillow See Now Opens a new window PharMeDoc Full Body U-Shaped Pillow See Now Opens a new window

⚠️ You can't see this cool product because you have ad block enabled.

Please whitelist our site to get all the best deals and offers from our partners. ad block enabled Leachco Snoogle Chic Supreme See Now Opens a new window Queen Rose Full Body Pregnancy Pillow See Now Opens a new window The 11 Best Pregnancy Pillows, Tested by 6 Tired Moms-to-Be View All Momcozy U-Shaped Pregnancy PillowSee NowOpens a new window

⚠️ You can't see this cool product because you have ad block enabled.

Please whitelist our site to get all the best deals and offers from our partners. ad block enabled Room Essentials Body PillowSee NowOpens a new window PharMeDoc Full Body U-Shaped PillowSee NowOpens a new window

⚠️ You can't see this cool product because you have ad block enabled.

What Other July 2026 Moms Are Talking About

There are 5,371 active discussions happening now with other July 2026 parents-to-be. Join in Recommended Reading

12 Cute Pregnancy Announcements to Celebrate Your Bundle of Joy
Here's What Getting the RSV Vaccine During Pregnancy Means for Your Baby’s Health
⚠️ You can't see this cool content because you have ad block enabled.
Please whitelist our site to get all the best deals and offers from our partners.
Flu While Pregnant: Symptoms & Safe Treatments
January Birth Flowers: Carnation and Snowdrop
What Is the Placenta — and How Does It Help Your Baby Grow?
Positive Microdeletion Screen? What It Means and Your Next Steps