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21 Weeks Pregnant: Symptoms & What to Know

21 Weeks Pregnant: Symptoms & What to Know

21 weeks pregnant

You’re past the halfway point! At 21 weeks pregnant, you’re in month five of your pregnancy, but in a few short weeks, you’ll be rounding the corner on month six (as well as the third trimester!). 

At this point in your pregnancy, you might be struggling with your changing body – from pregnancy weight gain to fatigue to stretch marks. Try focusing on activities that make your mind and body feel great, like reading or going outside for a walk. 

This week, your baby is the size of a banana. Their heartbeat is now loud enough to hear through a stethoscope, and it’s fast – about 120 to 160 beats per minute.

how big is my baby 21 weeks


21 Weeks Pregnant Symptoms


At some point during pregnancy, just about every parent begins to feel anxiety and maybe even a little fear. Who wouldn’t? There’s a huge change on the horizon for you and your family. 

If this is your first pregnancy, arming yourself with knowledge might help. Sign up for a childbirth class or take a look at our second-trimester pregnancy week-by-week breakdown to help take some of the unknown out of the coming weeks.

Finding time to relax and building a support system (even if it's online) can also help relieve symptoms of anxiety during pregnancy.

But if feelings of anxiety begin to overwhelm you, make sure to talk to your doctor. Anxiety is the most common mental health condition, affecting nearly 1 in 5 adults, including pregnant women, according to the American College of Obstetricians and Gynecologists (ACOG). Discuss pregnancy anxiety with your doctor or midwife as soon as possible so they can help you get help.

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Braxton Hicks Contractions

You may begin to feel “practice contractions” – also known as Braxton Hicks contractions. These uterine contractions are mostly infrequent, irregular, and painless. Some pregnant women never even notice them. 

Braxton Hicks contractions usually occur at the end of the day or when you’re dehydrated. You may also experience this tightening sensation when you have a full bladder or during other physical activities, including sex. 

This common pregnancy symptom is harmless, but it might be hard to distinguish from preterm labor. If you’re experiencing contractions that are regular – or any other signs of preterm labor such as pressure in your pelvis or cramping – call your doctor or midwife right away.

Hot Flashes

Is it hot in here? If you’re the only one in the room sweating, it’s likely thanks to pregnancy hormones and your heightened metabolism, the perfect recipe for hot and sweaty days and nights. Wearing loose clothing and drinking plenty of water can help you stay cool. 

Try writing down when you experience hot flashes to find out what is setting them off. Common triggers include hot drinks, spicy food, anxiety, and stress. Keeping a log can help you feel more prepared to discuss your hot flashes with your doctor or midwife at your next prenatal appointment. 


Feeling a little off balance lately? Your center of gravity changes as your belly grows, and it's best to avoid activities with a high risk of falling (no climbing ladders!). If you're wearing high heels at this point in your pregnancy, it might be time to make the switch to sneakers or flats. Lower-heeled shoes can also promote better circulation, which may help keep varicose veins at bay.

heels while pregnant

Baby on Board

At 21 weeks, your baby is around 10½ inches long and likely weighs between 11 and 12½ ounces. This week, growth measurement switches from crown-to-rump to crown-to-heel, as your baby’s legs are now included in the measurement. You may see a jump in growth because of this, but don’t worry – your baby still has a lot of room in there.

Did you know that your baby is swallowing a little bit of amniotic fluid each day? This helps babies practice swallowing and digesting (skills they'll need when they're born) while also getting nutrition and hydration.

Under Construction: Coordination

Your baby’s arms and legs are now in proportion, and cartilage is turning to bone. Additionally, neurons are now connected between their brain and muscles. This means that your baby has more control over their limb movements. So don’t be surprised if you feel more kicking and stretching in there. While it's not time to start counting kicks yet (you'll begin that around 28 weeks) it can still be fun to keep track of when and how often your baby is moving.

Under Construction: Reproductive Systems

It might be hard to wrap your head around the idea of future grandkids, especially if you’re a first-time mom, but your baby’s reproductive system is already in development. Girls will have a lifetime of eggs – about 6 million of them! Having a boy? His testes should drop in the coming weeks once his scrotum finishes developing. 

Under Construction: Bone Marrow

Before 21 weeks, your baby's liver and spleen were responsible for making blood cells. But at this point in fetal development, the bone marrow is developed enough to begin making its own blood cells. Bone marrow becomes the main site of blood cell production in the third trimester and will officially take the job over from the liver and spleen by the time your baby is born.

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What to Wear This Week

Made from breathable, lightweight fabric, our Bamboo Lounge Around Nursing & Maternity Tank is perfect for keeping you cool throughout pregnancy and while nursing your baby. With its gentle drape and built-in shelf bra with fixed padding, this tank will become your favorite piece of maternity clothing to wear around the house. Complete the look with our Bamboo Maternity & Postpartum Lounge Shorts for the ultimate comfortable yet stylish outfit that will help keep you cool in hot weather (or hot flashes). Did we mention these maternity shorts have pockets?

If you’re having night sweats, our French Terry Nursing Bra is a great solution for keeping the girls comfortable. This maternity bra’s soft fabric and light support are ideal for sleeping or lounging around the house. 

This information is for educational purposes only and does not constitute medical advice that has been medically reviewed. Please reach out to your midwife or doctor with any questions.

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