Conception Calculator — Week 28 From Conception (Fetal Age)
You are 28 weeks from conception, which corresponds to 30 weeks of gestational age (LMP-based). This page focuses on true fetal age — how long the baby has actually been developing since fertilisation.
Conception Calculator
Enter your LMP. Fetal age = gestational age − 2 weeks.
How to Use This Calculator
1. Enter the LMP date
Use the labelled fields and units that match your situation.
2. Calculate instantly
The result, visual comparison, and working update as values change.
3. Discuss the estimate with your clinician
Check assumptions, then copy, print, or share the calculation.
Practical Examples & Use Cases
| Starting date | Method | Calculation | Planning use |
|---|---|---|---|
| 1 Jan | LMP | +280 days | Estimated due date |
| Known clinical date | Ultrasound | Clinician dating | Confirm or revise estimate |
Baby at week 28
At 28 weeks from conception (30w gestational): Eyes can open and close. REM sleep begins — dreams possible. Fat continues accumulating.
Mother's body — what changes
28 weeks post-conception, your body is: Anti-D immunoglobulin injection if Rh-negative. Sleep on side — never on back.
Nutrition & supplements
Add ~450 kcal/day. Increase iron and DHA — brain growth peaks now. Split meals into 5–6 small portions to control heartburn and stable glucose. Week 28 from conception (30 weeks gestational) needs targeted micronutrients — the developmental window differs from LMP-based advice.
Safe exercise
Reduce intensity but keep moving. Pelvic floor + squats prepare for labour. Avoid contact sports, ski, horse-riding and hot yoga. At 28 weeks from conception, low-impact activity supports placental blood flow without stressing the fresh implantation.
Doctor visit checklist — week 28
- ✓Anti-D injection if Rh-negative; repeat GTT if flagged earlier
- ✓Note: 28 weeks from conception = 30 weeks LMP — clinic dating uses LMP
- ✓Confirm dating with crown-rump length at 8–13 weeks (±5 days accuracy)
Warning signs — call your provider immediately
- ⚠Heavy bleeding (soaking a pad in an hour)
- ⚠Severe abdominal pain that does not ease
- ⚠Fever above 38°C / 100.4°F
- ⚠Regular contractions before 37 weeks (preterm labour)
- ⚠Reduced fetal movement — fewer than 10 kicks in 2 hours
- ⚠Sudden swelling of face/hands + severe headache (preeclampsia)
- ⚠Bright red bleeding (placental abruption or previa)
Week 28 — Frequently asked questions
Content aligned with ACOG dating criteria and Mayo Clinic conception timeline. Reviewed by Dr. Maria Rehman, MD (OB/GYN). This page is educational and does not replace personal medical advice — call your obstetrician for any concern.
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