What is a Menstrual Cycle? The 4 Stages Explained

While you only bleed a few days out of each month, your body is going through a different phase of the menstrual cycle 24/7. What are the phases of the cycle? Read on for an explanation.

The following is an excerpt from Kt’s Period Guide, an e-book created to help teens navigate puberty and their first period with know-how and confidence. Download your copy today to learn everything there is to know about your body, the menstrual cycle, and more.


As a teenager, chances are you’ve heard the phrase “it’s just a phase” more than once in your life. Sorry about that. Adults are annoying. While people may or may not have phases, periods definitely do. The part of your menstrual cycle we refer to as the “period” is the first and most visible part of a larger process of phases and changes bodies go through to prepare for a potential pregnancy. If a pregnancy does not occur, the period begins, and the cycle starts again. 


The four stages of the menstrual cycle are:


Phase 1: The Follicular Phase

Phase 2: The Ovulation Phase

Phase 3: The Luteal Phase

Phase 4: The Menses Phase


The Stages of the Menstrual Cycle, Explained

1: The Follicular Phase

DAYS: 14 (average)

The follicular phase is the first part of your menstrual cycle and begins right after your last period ends. During this phase, the ovary is maturing an egg within a sac (a.k.a. follicle) in preparation for the egg to be released. Basically, this is the time the egg spends getting ready before it says bye-bye to the ovary and hits the town.

Throughout this phase, estrogen levels gradually increase and get to their highest levels right before phase 2.

2: The Ovulation Phase

DAYS: 1 - 3

It’s time for that egg to hit the road! During the ovulatory phase, the egg is released from

the ovary’s sac. This is the part where Ms. Egg puts on her finest fit and heads down to club Fallopian Tube to see if there are any cute sperm worth talking to. (Have we taken this metaphor too far?)

3: The Luteal Phase

DAYS: 14 (average)

Here’s where things get interesting. Actually, scratch that, this is all pretty interesting. During the luteal phase, the sac (aka “corpus luteum”) produces a hormone called progesterone in preparation for a pregnancy. Now your cycle can split off in two ways: in one scenario, there is a pregnancy, and your body begins the preparation for carrying a child. In scenario two, there is no pregnancy (a.k.a Club Fallopian Tube was kind of busted). When there is no pregnancy, the corpus luteum sac dissolves (bye corpus luteum sac!), progesterone levels fall, and your period begins.

Which brings us to…

4: The Menses Phase (Your Period)

DAYS: 2 – 7

As we’ve already discussed, that stuff we call “period blood” is actually a combination of liquefied uterine lining tissue, blood, cells, and enzymes that flow from the uterus through the cervix to the vagina and out of the body. What a ride! According to the Mayo Clinic, your period can last anywhere from two to seven days, and how you feel during that time can vary wildly based on your genes and your biology. Here are some totally normal things you might expect while on our period (from the Society of Obstetricians and Gynaecologists of Canada): breast tenderness, muscle aches, abdominal cramps, headaches, lower back pain, low energy, fatigue, bloating, joint pain, acne, diarrhea or constipation, trouble sleeping.

That list may look like a lot, but most women only experience mild versions of only some of these symptoms. If you’re dealing with any of these symptoms, readily available medications like ibuprofen and naproxen can help. Warm baths, compresses, and plenty of fluids can also help ease the symptoms.


To read more download the Kt by Knix Period Guide here.

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