If you are trying to conceive,  knowing when to have intercourse is sometimes tough.  There is no alarm that goes off when women ovulate. Two things I suggest to my patients:  Try using an over the counter ovulation kit.  This narrows the window of when you should have sex.  Secondly, if you don’t want to do any tests, you can monitor your menstrual cycles with a calendar.  If you count back 14 days from the first day of your period then that is the day you probably ovulated.  Doing this allows you to find out how long your cycle is and predict when you may be the most fertile.