Trimester 1
3 weeks pregnant: Fertilisation and the first cells
Here is what to expect this week for you and your baby.
Baby Size Cumin seed (jeera) 0.15 cm A single fertilised cell — smaller than a grain of sand.
Baby Development
- Fertilization occurs — sperm meets egg
- Cell division begins rapidly
- Blastocyst forms with inner cell mass and outer shell
Common Symptoms
- Implantation bleeding (light spotting)
- Fatigue and tiredness
- Mild abdominal cramping
Tips & Advice
- Avoid heavy lifting and strenuous exercise
- Reduce caffeine intake to under 200mg/day
- Eat small frequent meals to manage nausea
Nutrition Guide
- Omega-3 fatty acids: walnuts, flaxseed (alsi)
- Folate-rich foods: methi leaves, beetroot
- Zinc: pumpkin seeds, chickpeas (chole)
Medical Checklist
When to see your doctor at week 3
Some symptoms need attention right away. Contact your doctor or go to the nearest hospital if you notice any of these:
- Heavy bleeding (soaking a pad within an hour)
- Severe or persistent abdominal or pelvic pain
- Fever above 38°C (100.4°F)
Frequently asked questions
Can I confirm pregnancy this week?
A beta-hCG blood test can sometimes detect pregnancy by 8–10 days post-ovulation. Home tests are reliable from a missed period.
When does implantation happen?
About 6–10 days after fertilisation — late this week or in week 4.
Is light spotting normal?
Implantation can cause light pinkish spotting for a day. Heavy bleeding is not normal — call your doctor.
For partners
Stock bland snacks (crackers, lemon) — early-pregnancy nausea may start soon.
Prepare for your OB visit
- Should we do a beta-hCG blood test now or wait?
- What lifestyle changes should start immediately?
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