The menstrual cycle has four distinct phases: menstruation, the follicular phase, ovulation, and the luteal phase. In a typical 28-day cycle, these phases follow a predictable sequence driven by shifting hormone levels, though healthy cycles can range anywhere from 21 to 35 days. Each phase brings its own hormonal profile, physical signs, and characteristic symptoms.
How the Four Phases Fit Together
A cycle is counted from the first day of one period to the first day of the next. In a textbook 28-day cycle, menstruation covers roughly days 1 through 5, the follicular phase overlaps with menstruation and continues until ovulation around day 14, ovulation happens mid-cycle, and the luteal phase fills the remaining two weeks from about day 15 to day 28.
In reality, these timelines shift from person to person and even from cycle to cycle. A period lasting anywhere from 2 to 7 days is considered normal. What stays consistent is the order of events and the hormonal logic connecting them: each phase sets the stage for the next.
Menstruation: The Shedding Phase
Menstruation marks both the end of the previous cycle and day 1 of the new one. It happens because estrogen and progesterone levels drop sharply when no pregnancy has occurred. Without those hormones sustaining it, the thickened uterine lining breaks down and sheds as menstrual blood.
Most periods last between 2 and 7 days. Common symptoms during this phase include cramping, lower back pain, fatigue, and headaches. Energy and mood tend to be at their lowest point in the cycle, particularly during the first day or two. Cervical mucus is minimal at this stage, and what’s present after bleeding ends is typically dry or sticky with a white or light yellow appearance.
The Follicular Phase: Building Up
The follicular phase begins on day 1 of your period (so it overlaps with menstruation) and lasts until ovulation. During this time, the pituitary gland releases follicle-stimulating hormone, or FSH. This hormone signals the ovaries to start developing follicles, which are small fluid-filled sacs that each contain an immature egg. Several follicles begin to grow, but typically only one becomes dominant and continues maturing.
As the dominant follicle grows, it releases increasing amounts of estrogen. That rising estrogen does two important things: it thickens the uterine lining to prepare for a potential pregnancy, and it eventually triggers the hormonal surge that causes ovulation.
The follicular phase is when most people feel their best. Energy levels climb, sleep improves, and bloating from menstruation fades. Many people notice increased motivation, confidence, and a general lift in mood as estrogen rises. Cervical mucus gradually changes too. In the days after your period, it starts out dry and pasty, then becomes creamy and yogurt-like around days 7 to 9, and finally turns wet, stretchy, and slippery (resembling raw egg whites) as ovulation approaches around days 10 to 14.
Ovulation: Egg Release
Ovulation occurs when a sharp spike in luteinizing hormone (LH) causes the dominant follicle to release its mature egg into the fallopian tube. In a 28-day cycle, this typically happens around day 14, though the exact timing varies. The egg survives for about 12 to 24 hours after release, making this the most fertile point in the cycle. Because sperm can survive in the reproductive tract for several days, the broader fertile window extends to roughly five or six days around ovulation.
You can sometimes feel ovulation happening. Some people notice a mild twinge or cramp on one side of the lower abdomen. Cervical mucus is at its most slippery and egg-white-like consistency, which helps sperm travel more easily. Basal body temperature, your resting temperature first thing in the morning, rises slightly after ovulation. The increase is small, typically less than half a degree Fahrenheit, though it can range from 0.4°F to 1°F. This temperature shift is caused by progesterone, which surges after the egg is released.
The Luteal Phase: Waiting and Winding Down
After ovulation, the now-empty follicle transforms into a temporary structure called the corpus luteum. Its primary job is to produce progesterone, the hormone that maintains and enriches the uterine lining so a fertilized egg could implant and grow. The luteal phase lasts from roughly day 15 to day 28.
If fertilization doesn’t occur, the corpus luteum gradually breaks down over about two weeks. Progesterone and estrogen levels fall, the uterine lining can no longer sustain itself, and menstruation begins, restarting the cycle. If the corpus luteum doesn’t produce enough progesterone during this phase (sometimes called a luteal phase defect), the uterine lining may not develop properly, which can affect fertility.
The luteal phase is when premenstrual symptoms show up. As progesterone rises and then falls, many people experience breast tenderness, bloating, food cravings, headaches, and digestive issues like constipation. Sleep quality often dips. On the emotional side, mood swings, irritability, sadness, anxiety, and fatigue are common. These symptoms tend to intensify in the final days before your period. Cervical mucus dries up quickly after ovulation, returning to a dry or barely noticeable state for most of the luteal phase.
Tracking Your Own Pattern
Because healthy cycles range from 21 to 35 days, your phases won’t always line up with the textbook 28-day model. The follicular phase is the most variable part. Stress, illness, travel, and weight changes can all delay or accelerate follicle development, which shifts when ovulation occurs and changes your total cycle length. The luteal phase, by contrast, tends to stay relatively consistent at around 12 to 14 days for most people.
Two simple tools can help you identify where you are in your cycle. Cervical mucus follows a visible progression from dry and sticky after your period, to creamy mid-follicular, to wet and egg-white-like near ovulation, and back to dry during the luteal phase. Basal body temperature, taken at the same time each morning before getting out of bed, will show a small but sustained rise after ovulation that stays elevated until your next period. Together, these signs give you a practical map of your own cycle’s timing without relying on calendar math alone.