The menstrual cycle is a 21-35 day hormonal cycle during which estrogen and progesterone levels change to prepare the body for pregnancy. As hormones change throughout the month, you will experience four phases of the menstrual cycle: menstrual, follicular, ovulation, and luteal phase. 

These phases all have distinct symptoms that affect your mood, fertility, and how your body looks and feels. Understanding your symptoms can help you pinpoint your menstrual cycle phase and better understand your body’s changing hormone levels. 

The menstrual cycle starts on the first day of your period, also known as menses or menstruation. It ends on the day before your next period. These phases can vary in length, and hormonal changes influence each phase.

Menstrual Phase (Menses)

Menses, or your period, kicks off the menstrual cycle and lasts up to eight days. During menses, low estrogen and progesterone levels help shed the uterine lining (endometrium). This shedding of blood and cells creates the menstrual fluid that exits from the vagina. 

Follicular Phase

The follicular phase typically lasts 10-16 days. During this phase, the body prepares to release an egg for fertilization. Estrogen levels increase to help thicken a new uterine lining. At the same time, several follicles (fluid-filled sacs in the ovaries) start to mature to prepare to release an egg. 

Ovulation Phase 

Ovulation lasts about 12-24 hours. During this phase, follicle-stimulating hormones (FSH) and luteinizing hormone (LH) cause a follicle to rupture and release an egg from the ovary (gland where eggs form). This egg travels through the fallopian tube to the uterus, the organ where a fetus develops during pregnancy.

Luteal Phase

The luteal phase occurs during the second half of the menstrual cycle after ovulation. It typically lasts about 14 days. During this phase, the ruptured follicle that released an egg turns into a mass of cells called the corpus luteum. The corpus luteum produces progesterone to help the uterus maintain its thick lining. 

If the egg is fertilized during ovulation, it will try to implant in the uterus. If implantation doesn’t occur, estrogen and progesterone levels drop to prepare for the uterine lining to shed, starting your period and restarting the menstrual cycle. If an egg does implant in the uterus, pregnancy begins.

Your body goes through different physiological and hormonal changes during each menstrual phase. As a result, you can often identify which menstrual cycle phase you’re in based on your symptoms. 

Menstrual Phase

The primary symptom of the menstrual phase is menstrual bleeding, which is your uterine lining shedding. You may also experience cramps and backache as your uterus contracts to release the uterine lining. Low estrogen and progesterone levels can also cause bloating, tender breasts, mood swings, acne, and food cravings. Low hormone levels and blood loss may also lead to fatigue.

Follicular Phase

During the follicular phase, you no longer have a period. You may notice no vaginal discharge for the first few days. Rising levels of estrogen can increase your energy levels and elevate your mood. Hormone changes may also cause an increased libido and clear skin. Further into the follicular phase, vaginal discharge can appear white, cloudy, or sticky due to an uptick in estrogen.

Ovulation Phase

During ovulation, your cervical fluid will appear clear and stretchy, similar to egg whites. You may also experience mild cramping on one side, known as mittelschmerz. You may also have an increased sex drive and tender breasts.

Luteal Phase

Higher progesterone levels during the luteal phase can lead to some noticeable symptoms. Your cervical mucus may appear thick, pasty, or sticky. Some people may also feel more stressed or anxious. As you reach the end of the luteal phase, you may experience premenstrual syndrome (PMS) symptoms, like mood swings, fatigue, bloating, and food cravings.

While you have probably heard a typical menstrual cycle is 28 days long, a regular cycle can last anywhere from 24-38 days. Some people may also experience irregular cycles that affect menstrual bleeding and cycle duration from month to month.

The average person loses 2-3 tablespoons of period blood each menstruation, but you may experience lighter or heavier periods. 

You may naturally have longer or shorter menstrual, follicular, or luteal phases that affect the length of your cycle. Menstrual cycle length and period flow can also vary due to health, age, and medications.

Menstrual cycles are typically longer during the first few years after your first period. As you enter your 20s and 30s, cycles start to regulate and stay within the 24-38 day range. As the body prepares for menopause later in life, menstrual cycles can become shorter or irregular. 

Other Factors Affecting Cycle Duration

Underlying health conditions like polycystic ovary syndrome (PCOS), endometriosis, uterine fibroids, or thyroid disorders can make your cycles longer and irregular. Stress can also alter hormone levels, which can shorten or lengthen your cycle.

Birth control methods like hormonal contraceptive pills often shorten your cycle to a specific timeline. Other birth control methods like an intrauterine device (IUD), implant, or shot can make your cycle irregular, longer, or shorter. 

Tracking the various phases of your menstrual cycle can help you feel more in tune with your body, know when to expect your period, help you get pregnant, or help you prevent pregnancy. 

There is more room for error when using only tracking methods to prevent pregnancy. Barrier methods (e.g., condoms) or other forms of birth control are typically more effective at preventing pregnancy.

Here are a few ways to track your menstrual cycle:

• Calendar: Mark your period’s start and end dates using a paper or digital calendar. From there, you can generally estimate that you’ll ovulate about 14 days after your period.
• Ovulation test strips: These can detect a surge in LH hormones, which indicates the start of ovulation. Begin testing 3-5 days before you estimate ovulation will start.
• Symptoms: Record your symptoms throughout the month to help you identify the length of each phase.
• Menstrual cycle tracking app: Apps like Flo or Clue can help you keep track of symptoms and durations for each phase. 
• Basal body temperature (BBT): Tracking your BBT can help you determine when you are in each phase. This involves taking your temperature right after waking up (your BBT). Your BBT increases by 0.5-1 degree Fahrenheit during ovulation. Your temperature will stay elevated through the luteal phase and drop a few days before your period.
• Symptothermal method: This combines tracking BBT with identifying changes in vaginal discharge during each phase.

Talk to your healthcare provider if your menstrual cycle lasts less than 24 or more than 38 days. You should also visit your healthcare provider if you have drastic changes or heavy bleeding during your menstrual period. Irregular cycle lengths and periods can sometimes signal an underlying health condition.

Menstrual period symptoms that warrant a visit to your healthcare provider include:

• Clots bigger than a quarter
• Bleeding for more than eight days
• Bleeding through pads or tampons every 1-2 hours
• Sudden high fever
• Painful periods that make it difficult or impossible to do daily tasks

You should also see a healthcare provider if you notice abnormal vaginal discharge, burning, rash, or itching. These symptoms can be a sign of an infection. Abnormal vaginal discharge can be bright yellow, green, thick and chunky, or gray. It may or may not have a foul odor.

The average menstrual cycle lasts 24-38 days and has four phases: menstrual, follicular, ovulation, and luteal. During each phase, hormones change and cause specific symptoms you can track.

The main symptom of the menstrual phase is the body shedding the lining of the uterus and having a period. During the follicular phase, the body prepares to release an egg, which can make you feel more energized and leave a white, sticky discharge.

When your ovary releases an egg during ovulation, you may notice clear, stretchy discharge and mild cramping. During the luteal phase, progesterone increases to prepare your body for implantation, and you may feel more stressed or moody.

Talk to your healthcare provider if you have concerns about your menstrual cycle or notice painful or abnormal symptoms.