Fertility basics
The follicular phase runs from the first day of bleeding to ovulation. Rising FSH recruits a group of follicles, one usually becomes dominant, and its oestrogen thickens the endometrium. Its length varies between people and between cycles, which is why ovulation day is not fixed.
Also known as: first half of cycle, pre-ovulatory phase
Related Canada guides
Sources
- Society of Obstetricians and Gynaecologists of Canada (SOGC) patient information
Last reviewed: September 9, 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.