Your baby is the size of a Poppy Seed. Discover exactly what is happening to your body and your baby this week.
Week 4 in detail
The embryo is organizing into three germ layers that will become brain and skin, muscle and bone, and gut. The neural plate is forming. A home test is often positive this week because hCG is rising.
A missed period is the usual first clue. Breast tenderness, fatigue, and bloating can start as hCG and progesterone rise. Light spotting can still happen. Soaking pads is a reason to call a clinician, not to wait for the next week page.
Take a test with first-morning urine, then call for your first appointment. Insurance or public-clinic waitlists can be long. The checklist above is the action list; this is the medical context.
A general guide, not medical advice. Scan timing and symptoms vary — ask your clinician.
This chart visualizes the average length of the baby from week 1 to 40. Values are based on standard clinical averages.