It's a common misconception that your cycle length is how many days you bleed while on your period. What your cycle length really is, is the number of days between the start of your period to the day before your next period starts again.

The average woman as a 28 day cycle, with ovulation occuring on day 14 but cycle length can vary greatly from woman to woman. In order to use our ovulation calendar, you need to know how long your cycle really is.

Just enter the date that your last two periods started and we will calculate the number of days in your cycle for you. If the number of days is in your cycle is less than 21 days or more than 35 days, the ovulation calendar will not be able to accurately predict when you are most fertile.

Date Period Started in First Month:


Date Period Started in Next Month:

Your cycle length:  days.

Now that you know how long your cycle is, you can go back to the ovulation calendar and calculate when you will be most fertile.

You might benefit from a fertility supplement if:

  • You have very short cycles of less than 21 days.
  • You have very long cycles of more than 35 days.
  • Have irregular periods where you do not have a period every month or the number of cycle days varies widely form month to month.