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First TrimesterWeek 4 of 40

Pregnancy Week 4: The Positive Test

Updated

Your baby this week
About the size of a poppy seed
~0.04 in · ~<0.01

Medical Disclaimer: Content is for informational purposes only and does not replace professional medical advice. Always consult your healthcare provider.

How your baby is growing this week

Poppy-seed size — about 0.04 inches. Implantation is complete, and the embryo has organized into three layers that will form every organ, bone, and nerve. The neural tube — the foundation of the brain and spinal cord — is beginning to form this week and next.

What your partner is going through

Missed period confirmed. hCG doubling every 48 hours — causing fatigue, breast tenderness, and possible nausea. Emotional whiplash between excitement and terror is standard.

What to focus on this week, dad

  • 01Start the Protocol folder — one shared Google Drive or Notion doc for insurance cards, OB contact, pharmacy, appointment notes, and the questions you'll accumulate fast. Everything for the next nine months lives in one place.
  • 02Calculate the due date (last period + 280 days) and count backward now to map your parental leave. The earlier you flag the timeline to your employer, the smoother it goes.
+1 more focus item in the full briefing for week 4 — Start free

Connect with your partner

Do not pressure her to feel happy immediately. Fear, ambivalence, and overwhelm are all normal first reactions. Match her energy — if she needs to process quietly, sit with her.

Source: Mayo Clinic

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