Estimate conception about 266 days before the due date.
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Use the date you know or remember most clearly.
Estimate a possible conception date from your due date, last menstrual period, or ovulation date, then see approximate pregnancy details.
Estimate conception dateUse the date you know or remember most clearly.
When the calculated date falls within an ongoing pregnancy, the page also shows the current gestational age, trimester, and approximate baby size.
Estimate conception about 266 days before the due date.
Ovulation is estimated from your average cycle length, but the actual day can shift by several days.
The result clearly explains the uncertainty rather than claiming an exact conception day.
Move easily from cycle tracking to ovulation, gestational age, due date, conception date, and a week-by-week chart.
All results are estimates intended to provide a helpful overview. They do not replace an ultrasound, diagnosis, or medical advice. Length is shown around a weekly reference value. Weight ranges from week 22 use the 10th-90th percentiles from the INTERGROWTH-21st standard.
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