How many days after the first day of your last period are you fertile?
Fertility Day helps you with a simple and clean interface.

Learn how to find out when you're the most fertile based on your menstrual cycle. In general, a woman's fertile window is the day of ovulation (usually 12 to 16 days before the menstrual period begins) and the five days preceding it. For the average woman that occurs somewhere between days 10 and 17.