Menstrual Cycle Phases – What Happens During Each Stage?
Your menstrual cycle moves through four distinct phases — menstrual, follicular, ovulation, and luteal — each driven by a different balance of hormones. This guide breaks down what happens in your body during each stage, how long they typically last, and what’s considered a normal range.
Every month, your body moves through four distinct menstrual cycle phases, a natural hormonal process that prepares the body for a possible pregnancy whether or not you’re trying to conceive. Understanding your menstrual cycle phases can help you predict your next period, identify your fertile window, recognize ovulation, and better understand your overall reproductive health.
Each of the menstrual cycle phases is controlled by a shifting balance of hormones, mainly estrogen, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Although 28 days is often cited as the cycle “average,” a healthy cycle can range anywhere from 21 to 35 days, and the length of individual phases varies from person to person.
Want to know which menstrual cycle phase you’re currently in? Use our Period Calculator to estimate your next period, ovulation day, fertile window, and upcoming cycles.
On this page:
What Are the Phases of the Menstrual Cycle?
Your menstrual cycle is made up of four menstrual cycle phases that repeat roughly every month: the menstrual phase, the follicular phase, ovulation, and the luteal phase. Each one is driven by a different balance of hormones, and together they prepare your body for a possible pregnancy each cycle — whether or not that’s the goal.
These stages of the menstrual cycle aren’t perfectly separate blocks of time; the menstrual and follicular phases actually overlap for the first several days. Understanding what’s happening in each stage can make patterns in your period, energy, and mood easier to make sense of.
Menstrual Cycle Timeline
Here’s a quick overview of the four menstrual cycle phases in a typical 28-day cycle:
| Phase | Days | Main Hormone | Main Event |
|---|---|---|---|
| Menstrual | 1–7 | Low estrogen & progesterone | Bleeding |
| Follicular | 1–13 | FSH + Estrogen | Egg develops |
| Ovulation | Around Day 14 | LH | Egg released |
| Luteal | 15–28 | Progesterone | Uterus prepares |
This table reflects an average 28-day cycle. If your own cycle runs shorter or longer, the days shift, though the overall order of the menstrual cycle phases and hormonal pattern stays the same.
The Four Phases, Day by Day
Here’s a closer look at what happens in your body during each of the four menstrual cycle phases.
Day 1 of your cycle is the first day of visible bleeding. This phase happens because, without a fertilized egg from the previous cycle, hormone levels drop and the thickened uterine lining sheds. Both estrogen and progesterone are at their lowest points during this phase, which is part of why some people feel more tired or low-energy during their period.
The follicular phase technically starts on day 1 too, running alongside the tail end of your period and continuing after bleeding stops. During this time, follicle-stimulating hormone (FSH) prompts several follicles in the ovaries to develop, each containing an immature egg. Usually one follicle becomes dominant, and rising estrogen from that follicle signals the uterine lining to start rebuilding. This is generally the phase where energy tends to pick back up.
A surge in luteinizing hormone (LH) triggers the dominant follicle to release its egg — this is ovulation. It’s typically the single most fertile point in the cycle, since the released egg is available to be fertilized for roughly 12 to 24 hours. Some people notice signs like a change in cervical mucus or mild pelvic twinges around this time, though not everyone does.
After ovulation, the ruptured follicle transforms into a temporary structure called the corpus luteum, which produces progesterone to prepare the uterine lining for a possible pregnancy. If the egg isn’t fertilized, the corpus luteum breaks down, hormone levels drop, and the cycle restarts with a new period. The luteal phase is fairly consistent in length — usually close to 14 days — even when the rest of the cycle varies, which is part of why it’s used to estimate lower-risk and fertile days.
How Hormones Change During the Menstrual Cycle
Four main hormones drive the menstrual cycle phases, rising and falling in a coordinated pattern that moves you from one phase into the next.
Follicle-Stimulating Hormone (FSH)
FSH is released by the pituitary gland and, as its name suggests, stimulates a group of follicles in the ovaries to start developing early in the cycle. Each follicle contains an immature egg; usually one becomes dominant and continues maturing toward ovulation while the others recede.
Estrogen
Estrogen rises as the dominant follicle develops during the follicular phase. Beyond supporting the maturing egg, it also signals the uterine lining to rebuild and thicken after menstruation, and it’s part of what triggers the LH surge that leads to ovulation.
Luteinizing Hormone (LH)
A sharp surge in LH is what actually triggers ovulation, causing the mature follicle to rupture and release its egg. This surge is what ovulation predictor kits are designed to detect, since it typically happens 24 to 36 hours before the egg is released.
Progesterone
After ovulation, the ruptured follicle becomes the corpus luteum, which produces progesterone through the luteal phase. Progesterone’s job is to prepare and maintain the uterine lining in case a fertilized egg needs to implant. If pregnancy doesn’t occur, progesterone (along with estrogen) drops, which is what triggers the uterine lining to shed and the next period to begin. For a closer look at how these four hormones interact and feed back into each other, see our full guide on how hormones change during the menstrual cycle.
| Hormone | Role | Peaks During |
|---|---|---|
| FSH (follicle-stimulating hormone) | Stimulates follicle development | Early follicular phase |
| Estrogen | Matures the egg, rebuilds uterine lining | Late follicular phase |
| LH (luteinizing hormone) | Triggers egg release | Just before ovulation |
| Progesterone | Prepares and maintains uterine lining | Luteal phase |
How Cycle Length Affects Phase Timing
A normal cycle can range from 21 to 35 days, and most of that variation across the menstrual cycle phases happens in the follicular phase — the time it takes a follicle to mature can differ from person to person and cycle to cycle. The luteal phase, by contrast, tends to stay close to 14 days regardless of overall cycle length. This is why a shorter cycle usually means earlier ovulation, rather than a shorter luteal phase. Someone with a 24-day cycle shouldn’t assume ovulation happens on day 14 — it’s likely earlier — and the reverse is true for longer cycles.
What Can Disrupt the Normal Cycle?
Timing of the menstrual cycle phases can shift for a wide range of reasons, including stress, significant weight changes, intense exercise, illness, pregnancy, breastfeeding, hormonal contraception, puberty, and perimenopause. Conditions like PCOS, thyroid disorders, and other hormonal or reproductive issues can also affect cycle length and phase timing specifically.
Stress deserves a closer look, since the connection isn’t just anecdotal. Elevated cortisol, the body’s main stress hormone, can suppress gonadotropin-releasing hormone (GnRH) — the same signal that kicks off the whole hormonal chain described above. When GnRH is suppressed, follicle development can be disrupted, ovulation can be delayed or skipped entirely, and overall cycle length can shift. This is one physiological reason chronic stress, not just a single stressful day, tends to have a bigger effect on cycle regularity than short-term stress.
An occasional shift doesn’t necessarily point to a problem — but a pattern that persists over several cycles is worth mentioning to a doctor, especially alongside symptoms like very heavy bleeding, bleeding between periods, or periods that stop unexpectedly.
How to Track Your Cycle Phases
Tracking the menstrual cycle phases starts with recording the first day of each period, since that’s Day 1 of every phase count. From there, noting your period’s length, any cervical mucus changes, ovulation-related symptoms, and how you feel in the days before your next period can help you recognize your own pattern over a few cycles.
Our Period Calculator can estimate your next period from that history, our Ovulation Calculator can estimate when ovulation is likely to occur, and our Safe Days Calculator can estimate your fertile and lower-risk days. All three are estimates based on averages — they can’t pinpoint the exact day of ovulation, especially if your cycles are irregular.
Some people also use this same phase-by-phase awareness of the menstrual cycle phases for cycle syncing — adjusting workouts, meals, or workload to match how they tend to feel in each phase (more energy in the follicular phase, for example, versus wanting more rest in the luteal phase). Evidence for cycle syncing as a formal health practice is still limited, but tracking your own energy, mood, and symptoms phase by phase can still be a useful way to understand your own patterns, even without treating it as a strict protocol.
Signs and Symptoms to Expect in Each Phase
Physical and emotional symptoms often shift alongside the menstrual cycle phases:
- Menstrual phase: cramping, fatigue, and lower energy are common as hormone levels bottom out.
- Follicular phase: energy and mood often improve as estrogen rises.
- Ovulation: some people notice clearer, stretchier cervical mucus, a small rise in basal body temperature, or brief one-sided pelvic discomfort.
- Luteal phase: premenstrual symptoms — bloating, breast tenderness, mood changes — are common in the days leading up to the next period, especially later in this phase.
Everyone’s experience varies, and some people notice very few symptoms tied to phase changes at all.
Common Myths About Menstrual Cycle Phases
Reality: Day 14 is just an average for a 28-day cycle. Ovulation timing varies based on your actual cycle length and can shift from month to month.
Reality: A normal cycle can range from 21 to 35 days; 28 is simply the most commonly cited average.
Reality: Because sperm can survive up to 5 days in the reproductive tract, sex in the days before ovulation can still result in pregnancy, even if ovulation hasn’t happened yet.
When to Talk to a Doctor
Consider checking in with a doctor if: your cycle length changes significantly and persistently, your period is consistently late or unpredictable, you experience very heavy or prolonged bleeding, or symptoms in any phase are severe enough to disrupt daily life. Conditions like PCOS or thyroid issues can affect the menstrual cycle phases specifically, so a pattern worth flagging is worth mentioning.
Frequently Asked Questions
Common questions about the menstrual cycle phases, answered.