The four phases
Menstrual phase
(Days 1–5, approx.)
This phase begins on the first day of bleeding. Hormone levels (estrogen and progesterone) are at their lowest, which triggers the shedding of the uterine lining. Many people feel lower energy or more inward-focused, making this a natural time for rest and gentle care.
Follicular phase
(Days 1–13, approx.)
Overlapping with menstruation at the start, this phase is when follicle-stimulating hormone (FSH) helps ovarian follicles mature. Estrogen begins to rise, rebuilding the uterine lining and often boosting energy, focus, and mood.
Ovulation phase
(Around Day 14, approx.)
A surge of luteinizing hormone (LH) triggers the release of a mature egg. Estrogen peaks, and many people feel their most confident, energetic, and social during this time. Since this is the fertile window, it’s important for both conception and contraception planning.
Luteal phase
(Days 15–28, approx.)
After ovulation, progesterone rises to prepare for a potential pregnancy. If no pregnancy occurs, progesterone and estrogen drop, often leading to premenstrual symptoms like mood swings, cravings, or fatigue. This is a good phase for extra rest and self-care.