Monthly tracker :P
http://www.windowsphone.com/en-us/store/app/monthly-tracker/cdefb3e4-c27a-e011-986b-78e7d1fa76f8
Period tracker :rofl:
http://www.windowsphone.com/en-us/store/app/period-tracker/8f6503df-1923-44e6-93ba-c837d17c659f
Fertility diary free...