Week 3 Size: Microscopic Blastocyst
Smaller than a grain of salt.
Relative Visual Scale
Solid circle represents your baby's size. Dotted circle shows the full-term week 40 size threshold.
Baby's Development
The fertilized egg (zygote) divides rapidly as it travels down the fallopian tube. It becomes a hollow ball of cells called a blastocyst and begins to implant into the uterine lining.
Weekly Milestones
- ✦ Fertilization
- ✦ Implantation Initiated
Your Body & Symptoms
Implantation triggers the production of hCG (human chorionic gonadotropin), the hormone detected by pregnancy tests. You won't feel this yet, but your body is undergoing a massive shift.
Common Symptoms this Week
Doctor & Care Recommendations
- ✓ Continue taking prenatal vitamins.
- ✓ Keep eating nutrient-dense foods, focusing on leafy greens, lean proteins, and whole grains.
- ✓ Rest when you feel tired; early hormonal changes are starting to drain your energy.
Weekly Health Guides & Resources
First Trimester Guide
Read comprehensive clinical milestones, screening checklists, and developmental guidelines for this phase.
Track & Relieve Symptoms
Learn why symptoms occur, home remedies, and clinical indicators for this week:
Food Safety Checklists
Verify safety statuses, listeria and mercury risks, and safe alternatives for:
Frequently Asked Questions: Week 3
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