How to Calculate Ovulation Period Women\’s ovulation period is the key to pregnancy, so it is very important to know your own ovulation period. So, how to calculate your ovulation period? 1. Calendar method The calendar method is one of the simplest methods. A woman\’s ovulation period is usually the 14th day of her monthly menstrual cycle, so you only need to know the time of your last menstrual period and add 14 days to calculate the ovulation period. For example, if your last period started on January 1st, then ovulation will be around January 14th. 2.Body