How is pregnancy due date calculated?+
Pregnancy due date is calculated using Naegele's Rule: EDD = First day of Last Menstrual Period (LMP) + 280 days (40 weeks). Alternative: EDD = LMP + 9 months + 7 days. For cycles other than 28 days: adjust by the difference from 28 days. Example: LMP = 1 January 2026, cycle = 30 days. EDD = 1 January + 280 days + 2 days (30–28) = around 9 October 2026.
How accurate is the pregnancy due date calculator?+
The calculated EDD is an estimate. Only about 4–5% of babies are born exactly on their due date. Most births occur within 2 weeks before or after the EDD (between 38–42 weeks). An ultrasound scan (especially crown-rump length measurement in the first trimester at 8–12 weeks) gives a more accurate EDD than LMP-based calculation.
What are the three trimesters of pregnancy?+
First Trimester (Weeks 1–13): Conception to 13 weeks — organ formation, morning sickness common. Second Trimester (Weeks 14–27): 14 to 27 weeks — 'golden period', less nausea, movement felt. Third Trimester (Weeks 28–40): 28 weeks to delivery — rapid baby growth, increased discomfort. Key milestones: Heartbeat detectable at 6–8 weeks, gender visible at 18–20 weeks, viability at 24 weeks.
How to calculate due date from IVF?+
For IVF (In Vitro Fertilisation): Day 3 embryo transfer: EDD = Transfer date + 263 days (37 weeks + 4 days). Day 5 blastocyst transfer: EDD = Transfer date + 261 days (37 weeks + 2 days). The LMP equivalent for IVF: Day 3 transfer: EDD = Transfer date – 17 days, then + 280 days. Day 5 transfer: EDD = Transfer date – 19 days, then + 280 days.
What are signs of pregnancy before missing period?+
Early pregnancy signs (before missed period): Implantation bleeding (light spotting 6–12 days after conception), Breast tenderness and swelling, Fatigue, Increased urination, Mild cramping, Heightened sense of smell, Nausea (morning sickness can start as early as 2 weeks after conception). Home pregnancy tests detect hCG hormone and are accurate from the first day of missed period (some brands: 5 days before).
What is the safe period or fertile window for pregnancy?+
The fertile window is approximately 6 days ending on ovulation day. Ovulation typically occurs 14 days before the next period. For a 28-day cycle: ovulation around day 14; fertile window = days 10–15. For a 30-day cycle: ovulation around day 16; fertile window = days 12–17. Pregnancy is most likely when intercourse occurs 1–2 days before ovulation. Track using ovulation predictor kits (OPKs) or basal body temperature (BBT).