Ovulation Date:
Formula: Ovulation Date = Last Period Start Date + (Cycle Length - 14) days
Ovulation typically occurs about 14 days before the start of the next period. By subtracting 14 days from the cycle length, we estimate the ovulation date.
Fertile Window:
Formula: Fertile Window = Ovulation Date - 5 days to Ovulation Date + 1 day
The fertile window includes the days leading up to and just after ovulation, as sperm can survive for up to 5 days in a woman’s reproductive tract, and the egg can be fertilized for up to 24 hours after ovulation.
Next Period Start:
Formula: Next Period Start = Last Period Start Date + Cycle Length days
The next period is expected to start after the length of the current menstrual cycle.
Pregnancy Test:
Formula: Pregnancy Test Date = Next Period Start Date + 1 day
Pregnancy tests are usually recommended one day after a missed period for more accurate results.
Due Date If Pregnant:
Formula: Due Date = Ovulation Date + 38 weeks
Pregnancy is typically calculated to last about 40 weeks from the start of the last period, which is approximately 38 weeks from ovulation.