Log Your Symptoms In Flo: Discharge, Acne, Heavy Periods, and Get Health Insights and more. Track Your Menstrual Cycle And Know More About Every Cycle Phase. The follicular phase, ovulation, and the luteal phase: all menstrual cycle phases are explained at Flo, and you can track them. Planning to have a baby? Flo will tell you when your ovulation day and fertile window PCOS? Irregular cycle? Flo helps to track menstruation and ovulation precisely. How to get pregnant as soon as naturally possible? Flo Health Library has lots of Medically Accurate Info and Helps you track your fertile days.