ovulationWork out the length of your average menstrual cycle. Day one is the first day of the menstrual period and the last day is the day before the next period begins.

Ovulation happens about two weeks before the next expected period. So if your average menstrual cycle is 28 days, you ovulate around day 14.

Remember the ‘fertile window’ is the six days leading up to and including ovulation.

The three days leading up to and including ovulation are the most fertile. Depending on your cycle length the most fertile days in the cycle varies:

  1. If you have 28 days between periods ovulation typically happens on day 14, and the most fertile days are days 12, 13, and 14.
  2. If you have longer cycles, say 35 days between periods, ovulation happens on day 21 and the most fertile days are days 19, 20, and 21.
  3. If you have shorter cycles, say 21 days between periods, ovulation happens on day 7 and the most fertile days are days 5, 6, and 7.