If you are actively trying to get pregnant, there’s more to it than having sex. You have to actually know when to have sex and the key to that is knowing your cycle. On average cycles are 28 days, however everyone has a different cycle length. In order to figure it out start keeping track on a calendar. Day 1 of bleeding is the start of your cycle and then count how many days until Day 1 of your next period … that is the number of days for your personal cycle. You are actually ovulating 14 days prior to your first day of bleeding. For example, if your next period will start on December 28, you’d actually be ovulating on December 14 … your window for conception would be December 11-December 16.