Is conception the same as ovulation?

Very close — fertilization happens within 12–24 hours of ovulation.

How does it compare to LMP dating?

Conception-based dating is roughly 14 days later than LMP if you assume a 28-day cycle.

Conception happens around ovulation. Add 266 days to that date for your estimated due date.

Conception date + 266 days (38 weeks) = estimated due date.

Conception typically occurs within 24 hours of ovulation, so this calculation is functionally equivalent to ovulation-based dating.

If you tracked ovulation or had limited intercourse around a known fertile window, you can estimate conception within 1–2 days.