Count the first day of your period as day 1 of your cycle
Determine your average cycle length
Subtract 14 days from your cycle length
The result is your estimated ovulation day
Example: a 28-day cycle usually ovulates around day 14
Example: a 30-day cycle usually ovulates around day 16
Example: a 26-day cycle usually ovulates around day 12
Track cervical mucus changes
Use ovulation predictor kits
Monitor basal body temperature
Record your cycle for several months for better accuracy