The [[1]] phase is the first part of the ovarian cycle. 

The follicular phase begins on the first day of menstruation and is the first part of the ovarian cycle. 

During this stage, the uterine lining thickens, and an ovarian follicle begins to mature. 

The follicle houses an egg, which is released during ovulation.

The follicular phase lasts until ovulation, which happens on day 14 of a 28-day menstrual cycle. 

The precise timing of ovulation, however, varies from cycle to cycle and from woman to woman.