About the Pregnancy Calculator
The Pregnancy Calculator estimates your conception date, fertile window, and ovulation period. Enter your cycle details and you receive estimated dates for family planning and pregnancy timing.
The calculation follows the standard cycle-based method: ovulation falls about 14 days before the next expected period, and the fertile window covers the five days before ovulation plus the ovulation day itself. You enter the first day of your last menstrual period and your average cycle length, so the calculator shifts the midpoint for shorter or longer cycles. The window extends before ovulation because sperm can survive several days in the reproductive tract. Track your period for a few months to confirm your typical cycle length, and consider a healthcare professional for important family planning decisions.
- Enter the first day of your last menstrual period.
- Enter your average cycle length in days, or use the default of 28.
- Review the estimated conception date, fertile window, and ovulation day in the results.