First Trimester · Week 4
4 Weeks Pregnant: As small as a poppy seed
Baby development
Your baby at 4 weeks
Your baby is still tiny — the embryo is now fully implanted in the uterus and the amniotic sac is beginning to form. One fascinating early step is that the placenta is already starting to develop, even before your baby looks anything like a baby yet.
Your body this week
What you might be feeling at 4 weeks
You might not feel pregnant yet — or you might notice a missed period, mild cramping, breast tenderness, and fatigue. Some women feel absolutely nothing, which is completely normal. Your body is just beginning to produce hCG and progesterone, hormones that will shape the next eight months.
From Shelbi
Shelbi Kohler · mother of seven · certified birth doula
I remember staring at that positive test like the world had just shifted on its axis — because it had. Seven pregnancies, and every single time, that first positive test made my heart race the same way. The shock doesn't go away just because you've done this before. What I wish someone had told me that first time: it's completely normal to feel more scared than excited. You don't have to be happy yet. You just have to breathe.
For you
This week is about getting through it
Scroll up to revisit your baby's development and Shelbi's encouragement for week 4. When you're ready, share this week with your partner.
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Related weeks
Keep following your pregnancy
Common questions
4 weeks pregnant: your questions answered
Can I take a pregnancy test at 4 weeks? +
Yes — by 4 weeks, hCG levels are typically high enough for a home pregnancy test to detect. Use your first morning urine for the most accurate result.
Is cramping normal at 4 weeks? +
Mild cramping is very common and usually normal, caused by the expanding uterus and implantation. However, severe or one-sided cramping, especially with bleeding, should be reported to your doctor.
Should I start prenatal vitamins? +
If you haven't already, start now. Folic acid (400-800 mcg) is especially important in early pregnancy for neural tube development.
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