The basics
What are the phases of the menstrual cycle?
A menstrual cycle has four parts: your period, the days before ovulation, ovulation itself, and the days after. It runs from the first day of one period to the day before the next, and for most people lasts 21 to 35 days. The part before ovulation changes length the most, which is why cycles differ.
How long is a cycle?
A cycle runs from the first day of one period to the day before the next. For most people that’s somewhere from 21 to 35 days, often around 28.
What happens in each part?
- Period. The lining of the womb sheds. Bleeding usually lasts 2 to 7 days, most often about 5.
- Before ovulation. An egg matures in the ovary and estrogen rises. This is the part that changes length the most, which is why cycles differ.
- Ovulation. An egg is released. The day moves around, so any date an app shows is an estimate.
- After ovulation. Progesterone rises. This part is steadier, about 12 days on average. If there’s no pregnancy, hormones fall and the next period starts.
Does ovulation always happen on day 14?
A study of more than 600,000 cycles found the textbook “ovulation on day 14” doesn’t hold for most cycles, and the same person’s cycle length usually shifted by a few days from month to month. Bodies aren’t calendars. Tracking shows you your own pattern.
Frequently asked questions
What is the follicular phase?
It’s the stretch from the first day of your period until ovulation, when an egg matures in the ovary and estrogen rises. It’s the part that changes length most from cycle to cycle.
What is the luteal phase?
It’s the days after ovulation, when progesterone rises. This part is steadier, about 12 days on average. If there’s no pregnancy, hormones fall and the next period starts.
Is day 1 the first day of bleeding?
Yes. Day 1 of your cycle is the first day of your period, and the last day of the cycle is the day before your next period starts.
Sources
Seventh is a free period and cycle tracker for iPhone and iPad, by doogud. This article is general information, not medical advice. If something feels wrong, see a doctor.
