Conception Calculator

Conception typically occurs about 14 days after the first day of your last menstrual period, assuming a regular 28-day cycle. However, this can vary significantly depending on your individual cycle length. Women with longer cycles may ovulate later, while those with shorter cycles may ovulate earlier.

If you know your due date from an ultrasound or your healthcare provider, you can work backward to estimate when conception occurred by subtracting 266 days (38 weeks). This reverse calculation is often more accurate than estimating from your LMP, especially if your cycles are irregular.

Knowing your conception date can be helpful for determining paternity if there is uncertainty, understanding your timeline of pregnancy events, and correlating symptoms with specific stages of early pregnancy. However, it is important to remember that the estimated date of conception is always an approximation, typically accurate to within a few days.