How to use the predictor:
Simply enter the date of the first day of your most recent period. Then enter the length of your menstrual cycle (ie the length of time between the first day of one period and the first day of the next).

The day highlighted in the results chart is the middle day of the three or so days of the month in which you are actively ovulating and most fertile.

Date of last period: 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 January February March April May June July August September October November December 2007 2008 Length of cycle: 25 26 27 28 29 30 31 32 33 34 35