The Menstrual Cycle

A drawing of a person riding a surfboard, the background is red adn the wave is light pink, like they are "riding the crimson wave" Illustration by Leona Leoni

The following text uses the word “pussy*” as defined by Pussypedia.

by Marisol Alanís

Editor’s Note: This article focuses on what happens physiologically during each phase. To read about how each phase can affect our feelings, see our article “The Menstrual Cycle and Feelings.”

People with pussies generally experience their menstrual cycle starting when their bodies are biologically preparing to reproduce during puberty. The cycle repeats until menopause. The four phases of the the menstrual typically last from 21 to 35 days total (sometimes up to 45 for young teens).1

Some pussies* are more regular than others, and regularity may change over time.1 If you keep track of your periods, you can notice changes that might mean something is off in your cycle. If your period symptoms are affecting your daily activities, you should talk to a doctor.

A note: the stages overlap, so if you’re thinking, “Hey! That happened in the last stage!” You’re right, it did. And that’s OK! These stages describe an ongoing process.


This stage lasts 3-7 days on average and is also known as your period. Menstruation is the first part of the cycle. It begins when your ovum (egg) from the previous cycle does not get fertilized, meaning you did not get pregnant. Your estrogen and progesterone drop. That causes your body to get rid of endometrium––the stuff that comes out of your vagina during your period that looks like blood––that is not used by the uterus because pregnancy did not occur. You may have: tender boobs, abdominal swelling (bloating), headaches, irritability, tiredness, and/or cramps.1

Why (TF) do I have cramps when I menstruate?

The uterus squeezes itself to expel endometrium. The walls of the uterus produce a substance called prostaglandins that activates the contractions (squeezing) necessary to get the endometrium out. These spasms and excess prostaglandins cause pain in the lower abdomen and lower back, which we call cramps.1,2

Part of your brain called the hypothalamus sends a message to the pituitary gland, telling it to release follicle-stimulating hormone (FSH). This sends a message to the ovaries to produce 5 to 20 follicles (immature eggs). Only the healthiest egg comes to mature, although in rare cases there may be more than one in the same cycle. The eggs that do not mature will be absorbed by the body.4

The mature follicle triggers the release of estrogen, which thickens the walls of endometrium in the uterus.1


This phase happens in the middle of the cycle (starting at approximately day 14) and only lasts one day. It is kicked off by high levels of estrogen which cause the release of the luteinizing hormone which instructs your body to release a mature egg from the ovary into the fallopian tube.1

The egg travels not through some kind of tube but just floats right through an empty space in your abdomen. Long finger-like structures called fimbria at the ends of the fallopian tube kind of shimmy around trying to swoosh the egg into the end of the tube.2

This is the most fertile period of the menstrual cycle. It is also the shortest phase of the cycle, lasting 24 hours. However, sex with a penis in the five days before ovulation can also lead to pregnancy since sperm can live up to five days inside of you when it’s nice and happy swimming around in the type of cervical mucus you have coating your vagina at this point in the cycle.4

Change and irregularities in your cycle make it hard to precisely calculate of the day of ovulation, but there are a few bodily signs that can give you clues:5

  • Vaginal discharge becomes thicker, stickier, and whiter than usual
  • A slight increase in body temperature (in order to detect this change, you must take your temperature daily)1
  • Very light spotting
  • Mild cramps or pain on one side of the pelvis (called Mittleschmerz!)4
  • Breast sensitivity
  • Abdominal inflammation
  • Libido increase
  • Sharpening of smell, taste and vision5

Interesting Fact: At birth, ovaries contain around two million follicles. More than half are absorbed by the body during childhood. Of the 400,000 follicles left at puberty, only between 300 and 500 will mature into eggs.4

Luteal Phase

This phase lasts from 11 to 17 days (14 days on average) from ovulation until the start of your next period.1

After the expulsion of the egg, a substance called corpus luteum is left inside the ovary. Corpus luteum secretes estrogen and progesterone to thicken the walls of the uterus to make it a nice home for a fertilized egg. If the egg is not fertilized, the corpus luteum will be absorbed by the body, and levels of estrogen and progesterone will then drop, causing the shedding of the endometrium (your period starts).2

This is the phase when you get, premenstrual syndrome (PMS) which can include:6

  • bloating
  • pain or swelling of breasts
  • anxiety
  • crying
  • fatigue
  • constipation
  • acne
  • Headaches
  • weight gain
  • changes in libido
  • Cravings
  • sleep problems
  • mood changes.

Though the causes are not fully understood, you can read about what researchers have been able to understand in the article about the menstrual cycle and feelings.

If you feel like shit, exercise! When performing a physical activity, the body releases endorphins that reduce pain and make you happier.3

Author’s Dedication: For those who have asked how bodies with pussies* work. For those who have contributed new knowledge that allows us to be surprised by and marvel at life by understanding its processes.

Translated from Spanish by Serena Koch


  1. Ernst, Holly, Watson, Stephanie. ”Stages of the Menstrual Cycle.” Healthline. (2017): <>.
  2. OBOS Anatomy & Menstruation Contributors. “Internal Organs: Uterus, Fallopian Tubes, Ovaries.” Our Bodies Ourselves. (2014): </book-excerpts/health-article/internal-organs-uterus-fallopian-tubes-ovaries/>.
  3. Conrad Stoppler, Melissa. “Endorphins: Natural Pain and Stress Fighters.” Medicine Net. (2018): <>.
  4. OBOS Anatomy & Menstruation Contributors. “Stages in the Menstrual Cycle.” Our Bodies Ourselves. (2014): </book-excerpts/health-article/stages-in-the-menstrual-cycle/>.
  5. American Pregnancy Association. “Signs of Ovulation.” Accessed 2020: <>.
  6. Mayo Clinic Staff. “Síndrome Premenstrual.” Mayo Clinic. Accessed 2020: <>.

This article was previously published in Pussypedia and is reposted with permission.

Related Stories & Conversations:

My Story: Living with Irregular Menstrual Cycles

My Story: Using the Pill to Manage Menstrual Health