How It Works

• • Due date is estimated as LMP + 280 days (40 weeks), following Naegele's rule.
• • Conception is assumed to occur around LMP + 14 days.
• • Trimesters: 1st (weeks 1–13), 2nd (weeks 14–27), 3rd (weeks 28–40).
• • Only an estimate — your healthcare provider can give a more accurate date via ultrasound.