Enter the date of your first day of last period. For example, if your last period began on 11th of the month and ended on 17th, your first day of last period would be 11th.
Select your average cycle length. To do this, calculate the number of days between the first day of your last to last period and the first day of your last period. For example, if in March, your period started on 12th and in April, your period started on 10th, your average cycle length is 30 days, the number of days between the two dates. To get a more accurate reading, however, follow the same process for 4 to 5 months. Let’s say, your average cycle length for periods across March to July are 30, 29, 27 and 30. Your average cycle length would be an average of these numbers, that is, 29.
Press on ‘Calculate’ to see your pregnancy chances as per your intercourse date and also for the entire month, so you can plan it accordingly. You can also use all RED colour dates as women’s “Fertility Windows”, if your intention is to get pregnant.