The follicular phase starts on the first day of menstruation and ends with ovulation. Prompted by the hypothalamus, the pituitary gland releases follicle stimulating hormone (FSH). This hormone stimulates the ovary to produce around five to 20 follicles (tiny nodules or cysts), which bead on the surface.

How do I know my follicular phase?

The follicular phase is often the longest part of your menstrual cycle. It's also the most variable phase. It begins on the first day of your period and ends when you ovulate. The average length of the follicular phase is 16 days .

What days are the follicular phase?

Follicular vs.

The follicular phase lasts between 11–27 days; 16 days is average. The luteal phase lasts between 11–17 days; 13 days is average.