Calculate pregnancy progression and estimated due date.
Understanding pregnancy tracking and gestational age calculation. Pregnancy duration: approximately 280 days (40 weeks) from last menstrual period (LMP) to due date. Due date calculation: LMP + 280 days (or LMP + 40 weeks). Naegele's rule: LMP + 9 months + 7 days = estimated due date. Menstrual cycle length variation: 28-35 days typical; longer cycles push due date later, shorter earlier.
Ultrasound dating: most accurate first trimester (±3-5 days), accuracy decreases with gestational age progression (±2-3 weeks third trimester). Conception timing: occurs approximately 12-16 days after LMP (during ovulation), 40-week pregnancy counts from LMP (not conception). Pregnancy trimester: first trimester (weeks 1-13, higher miscarriage risk), second trimester (weeks 14-20, safest period), third trimester (weeks 21-40, preparation for birth). Viability: babies born after 22-24 weeks have survival potential, risk decreases substantially after 28 weeks. Premature birth (before 37 weeks): complications more likely, neonatal intensive care may be needed. Overdue pregnancy (after 42 weeks): induction often recommended due to placental insufficiency risks.
Morning sickness: typically 6-8 weeks LMP (first trimester), indicates healthy hormone levels. Fetal development: heartbeat detectable 8-12 weeks, viability ultrasound 18-20 weeks, final growth ultrasound 32-36 weeks. Due date accuracy: only 5% of babies born exactly on due date; 90% within 2 weeks of estimated date. Multiple pregnancies: shortened gestation (twins average 35 weeks), earlier ultrasound dating essential. Prenatal care: regular appointments monitor mother/baby health, identify complications early. Understanding pregnancy timeline enables preparation, medical monitoring, realistic expectations for birth timing..