Somewhere around day 20 you feel like a different person from the one you were on day 10. Same body, same life, wildly different energy, appetite and patience. That is not in your head. It is four phases of hormones taking turns, and once you can see them on a chart the pattern stops being a mystery.
Here are the four menstrual cycle phases in one table, followed by what each one actually does to you, and the one big correction to the textbook version.
The 4 menstrual cycle phases at a glance
| Phase | Typical days | What hormones do | How you might feel |
|---|---|---|---|
| Menstrual | Day 1 to about day 5 (2 to 7 days of bleeding is normal) | Estrogen and progesterone are at their lowest; the uterine lining sheds | Tired, crampy, low energy; often relieved that PMS has lifted |
| Follicular | Day 1 to ovulation; about 14 to 21 days including your period | FSH grows follicles in the ovary; estrogen climbs steadily and rebuilds the lining | Energy and mood usually lift after bleeding ends; more social, more motivated |
| Ovulation | About 12 to 16 days before your next period (day 14 in a textbook 28-day cycle) | An LH surge releases the egg; estrogen peaks then dips | Often peak energy and libido; some notice a one-sided twinge or clear, slippery discharge |
| Luteal | Ovulation to the day before your period; about 12 to 14 days | Progesterone rises from the corpus luteum, then both hormones fall if there is no pregnancy | Calmer at first, then in the last 5 to 7 days: bloating, cravings, breast tenderness, mood swings |
The day numbers come from Cleveland Clinic and the NHS, both of which put a normal cycle anywhere from 21 to 35 days, with 28 as the average. Keep that range in mind. "Day 14" is an average, not an appointment.
Phase 1: the menstrual phase
Day 1 is the first day of real bleeding, not spotting. Estrogen and progesterone have both dropped to their lowest point, which is what triggers the lining to shed. The NHS puts bleeding at 2 to 7 days, usually about 5. Cramps, if you get them, are usually worst on the first day or two. Iron goes out with the blood, which is one reason many people feel flat and tired.
What helps: heat, rest, iron-rich food, and not scheduling anything heroic. Our guide to cramps at night covers the sleep side.
Phase 2: the follicular phase
Technically this starts on day 1 too, running underneath your period, and ends at ovulation. Follicle-stimulating hormone (FSH) does what its name says: it grows a batch of follicles in the ovary, one of which will win. As the winning follicle matures it pumps out estrogen, which rebuilds the lining and, for a lot of people, rebuilds mood and energy with it. The days after your period ends are, for many, the best stretch of the month.
Cleveland Clinic calls this the longest phase of the cycle, at 14 to 21 days, and it is also the most variable one. That variability is where most of the difference between a 24-day cycle and a 34-day cycle lives.
Phase 3: ovulation
A sharp surge of luteinising hormone (LH) tells the mature follicle to release its egg. The release itself is a window of about a day, though the fertile window is wider because sperm can survive for days. The NHS puts ovulation about 12 to 16 days before the start of your next period, which is a more useful way to count than "day 14", because the luteal phase is more consistent in length than the follicular one (the Endotext chapter on the normal cycle is the detailed version, if you want the full hormone plumbing). Some people feel a mild one-sided ache or notice slippery, clear discharge. Many feel nothing at all.
Phase 4: the luteal phase
The empty follicle turns into the corpus luteum and starts producing progesterone, which holds the lining in place in case of pregnancy. Progesterone also nudges your body temperature up slightly, slows your gut, and relaxes smooth muscle. If no pregnancy happens, the corpus luteum fades after roughly two weeks, both hormones fall, and the fall is what most of us experience as PMS: bloating, sugar cravings, sore breasts, a short fuse. Cleveland Clinic puts the luteal phase at roughly days 15 to 28 in a 28-day cycle. Then day 1 again.
What you eat in this window matters more than in any other, which is why our phase-by-phase food guide spends most of its time here.
The correction: your ovulation is probably not on day 14
This is the honest limitation of every chart, including ours. In 2019, researchers analysed more than 600,000 cycles from 124,648 app users who were tracking temperature and LH tests. The mean cycle was 29.3 days, not 28. The mean follicular phase was 16.9 days, with a range from 10 to 30. The mean luteal phase was 12.4 days, range 7 to 17. In other words, the average real ovulation landed around day 17, and the spread was enormous. A chart can tell you the order of the phases and roughly what each one feels like. It cannot tell you what day you are on. Only tracking can.
What we make and why
We built Girl Chocolate around the last week of the luteal phase, because that is the week the chart above turns rough. It is a dark chocolate bar made for your cycle, with magnesium and other functional ingredients, sold as a pouch of 8 bars so one pouch covers one cycle. It supports PMS relief* as one small habit inside a phase that needs several. If you would like to know which phase gives you the most trouble, the Period Type quiz is a two-minute start.
Print the free cycle phases chart plus a 3-month tracker to check it against your own days. 2 pages, PDF, no email needed.
Download the PDFSources
- Cleveland Clinic: Menstrual cycle (normal menstruation), overview and phases
- NHS: Periods
- Cleveland Clinic: Follicular phase of the menstrual cycle
- Cleveland Clinic: Luteal phase of the menstrual cycle
- Bull JR et al. 2019, Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles, npj Digital Medicine
- Reed BG, Carr BR, The normal menstrual cycle and the control of ovulation, Endotext (NCBI Bookshelf)
When to talk to a doctor
Cycles between 21 and 35 days, with 2 to 7 days of bleeding, are normal. See a doctor if:
- pain stops you doing your normal day;
- you bleed through a pad or tampon every hour;
- pain suddenly got much worse than usual, or your cycle length changed sharply;
- you have pain with a fever.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
