Learn everything about the menstrual cycle with Flo: luteal and follicular phases, ovulation, periods, fertility, symptoms, cramps, and much more!

There are two distinct cycle phases: the follicular phase and the luteal phase. 

The first day of menstruation marks the beginning of the follicular phase. During this phase, the uterine lining thickens in preparation for receiving a fertilized egg. At the same time, follicles in the ovaries grow and mature, and the follicle that will release an egg — called the lead follicle or the dominant follicle — is determined.

Ovulation occurs at the end of the follicular phase. It generally happens approximately 14 days before the next period. Ovulation is a key process that divides the two phases. During ovulation, the dominant follicle releases an egg.

After ovulation, the luteal phase begins, and the egg can be fertilized. If an egg is fertilized, it happens in the uterine tube. If conception doesn’t occur, the uterine lining sheds, and your period begins. 

Both the follicular and luteal phases are accompanied by different symptoms. Track your symptoms in Flo to get more accurate cycle predictions!