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Pregnancy Week By Week

4 Weeks Pregnant

Congratulations! If you know you're 4 weeks pregnant, you found out the news earlier than a lot of women do (because you took a test as soon as you missed your period, or even a few days before, instead of waiting a bit)—and you might be totally excited, or you might be getting used to the idea of having a baby. Either way, you may not be feeling any different (for now, at least), since early pregnancy symptoms don’t always kick in right away. Definitely celebrate this amazing news with your partner, but you may not want to tell the whole world… just yet. Your first call at week 4 of pregnancy should be to your doctor to schedule your first prenatal visit, where he or she will confirm your pregnancy with a urine or blood test.

How Big Is Baby at 4 Weeks Pregnant?

At 4 weeks pregnant, baby is smaller than a poppy seed—practically microscopic. Baby is now known as a blastocyst, a teeny ball of cells, and is busy settling into his or her new home (your uterus), prepping for all the crucial development that will happen over the next six weeks.

4 Weeks Pregnant Symptoms

The same pregnancy hormones that gave you that positive pregnancy test can also cause some of the more typical 4-week pregnancy symptoms. These hormone levels increase pretty quickly, so while it’s normal to be 4 weeks pregnant with no symptoms, brace yourself: nausea and vomiting may be in your near future. Here’s a bit of what to expect at 4 weeks pregnant:

  • Bloating. You may be a little puffed up thanks to the pregnancy hormone progesterone. Break out the comfy pants!
  • Mild cramping. At 4 weeks pregnant cramping might worry you, but it actually may be a sign that baby has properly implanted in the wall of your uterus. However, any severe cramping or pain at 4 weeks pregnant is something you should definitely tell your doctor about right away. He or she will want to examine you to rule out any problems.
  • Spotting. Light bleeding can also occur during week 4 as a result of implantation. Don't worry—this is totally normal too. But the same advice goes: If it’s a lot of blood, like a period or heavier, lasts for more than a couple days, or if you’re concerned in any way, see the doc.
  • Mood swings. It’s not your imagination. Your mood is going haywire mostly because of your fluctuating hormones. (But maybe also because of stress and because your mind is racing.) Pregnancy mood swings are most drastic during the first 12 weeks. After that, the hormones will level out a bit, making you less likely to cry at every life insurance commercial you see.
  • Morning sickness. Experts say that about 50 to 90 percent of pregnant women get some form of morning sickness (a.k.a. nausea and sometimes vomiting too). So even if you haven’t had an upset stomach yet, you probably will at some point. Morning sickness is usually at its worst around nine weeks and then slowly gets better, typically disappearing completely in the second trimester.
  • Fatigue. One of the most common four weeks pregnant symptoms is total exhaustion, as your body is working hard to grow that teeny ball of cells into an embryo.
  • Sore breasts. Yowch! Your boobs are swollen and tender because of those surging hormones telling your body, “There’s a baby coming. Better start prepping those milk ducts!”

4 Weeks Pregnant Belly

A 4 weeks pregnant belly might be a little bloated, but you almost certainly don’t look pregnant yet. Still, you need to start acting like a mom-to-be. And that means giving TLC to yourself and your tiny baby-to-be.

Baby is already undergoing important development at week 4 of pregnancy, so start taking a prenatal vitamin if you’re not already. Look for one with at least 400 micrograms of folic acid and remember to take it daily. We know you’ve got a lot on your mind, but since folic acid is proven to help prevent birth defects, this is super important!

As your skinny jeans get more difficult to button, don’t shy away from looser clothing styles. Think stretchy pants, leggings, drapey shirts, and waterfall cardigans. There are a ton of loose-fitting clothing options that will help you look stylish and stay comfy.

4 Weeks Pregnant Ultrasound

During week 4 of pregnancy, the ball of cells is splitting into the embryo (your future child) and placenta. Baby's neural tube, the building block of the spine, brain, and backbone, is already formed. The amniotic sac and fluid are forming into protective cushioning for your baby. And on a 4 weeks pregnant ultrasound, all of that just looks like a tiny dot, called the gestational sac.

Chances are, though, you won’t have an ultrasound at 4 weeks. When you call the OB to tell him or her that you’re 4 weeks pregnant, they might tell you congrats and then have you make your first prenatal appointment for about a month from now. We know it seems like an eternity to wait. But if you have a clean bill of health and no risk of pregnancy complications, there simply isn’t a need to be seen by a doc just yet. There will be much more for the OB to see (including a heartbeat!) around week eight or nine. In the meantime, eat well, drink lots of water, avoid unhealthy habits like drinking and smoking, and try to relax. Just try.

Pregnancy Checklist at 4 Weeks Pregnant

Reminders for the week: