Week 4

First Trimester

A Positive Result

Your baby has implanted and hCG levels are rising — a home pregnancy test can now turn positive. The journey is officially confirmed.

Positive pregnancy test

This week's tip

💡 If pregnancy is confirmed, take a deep breath and be gentle with yourself — your emotions right now are completely valid, whatever they are.

Baby this week

🌾

About the size of

a sesame seed

Length

0.1 cm

Development

  • The embryo is now implanted in the uterine lining.
  • Three distinct layers are forming: ectoderm (skin, brain), mesoderm (muscles, heart), and endoderm (lungs, gut).
  • The placenta and amniotic sac are beginning to form.
  • hCG hormone production is high enough to detect on a home test.

How you might feel

  • A missed period is often the first sign.
  • Breast tenderness or fullness may begin.
  • Mild cramping and bloating are common.
  • Fatigue may start — your body is working around the clock.

Things to do this week

  • Take a home pregnancy test if your period is late
  • Call your OB or midwife to schedule your first prenatal appointment
  • Continue prenatal vitamins with folic acid
  • Avoid alcohol, smoking, and unnecessary medications

When to contact your care team

This is general guidance, not medical advice.

  • Contact your care team if you experience sharp one-sided pain and a positive test — this could indicate an ectopic pregnancy.
  • Contact your care team if you have heavy bleeding with a positive test.

Partner tip

If the test is positive, celebrate gently and talk about who you want to tell and when — decisions you make together.