Everything You Need to Know About the Four Phases of the Menstrual Cycle

Everything You Need to Know About the Four Phases of the Menstrual Cycle

Pop quiz! Do you know what the four phases of the menstrual cycle are? Do you know the hormones responsible for your cycle from start to finish?

Did we catch you off guard with all these questions?

For some of us, it’s been a while since our school days. But for others of you, it may be brand new information.

Either way, if you have a uterus and a period, this is the most important information that you can know about your body. We realize that not all education is created equal. But today, we’re here to level the field and keep you in the know.

Because knowledge is power, always.

What is the Menstrual Cycle?

Why do we go through a monthly cycle anyway? In short, the menstrual cycle is to prepare the uterus for pregnancy. Your body has eggs that can potentially become a baby some day - should you choose to have one.

Menstruation is the process of the egg moving through the ovaries to the fallopian tubes, to the uterus. If it’s an unfertilized egg, then the four phases start all over again. This cycle continues until you go through menopause which is when your ovaries stop producing hormones and have no more eggs.


This is the phase that everyone is the most familiar with. The bleeding. The cramping. Your energy is at an all time low. Welcome to the menstruation period, or as we commonly refer to it: A Period. It’s the shedding of the uterine lining which consists of blood, mucus, and tissue.

On average, you lose about 2-3 tablespoons worth of blood. (We know. It feels like so much more.)

Your period may last anywhere from 3-7 days, but some can have a period that lasts longer.

Your estrogen and progesterone levels are at an all time low. This explains why you don’t want to do anything by the time your period happens.


The follicular phase is when your body is preparing to release an egg. On average, this phase lasts for about 16 days, but can vary based on your cycle. Of the other phases, this one is the longest.

The follicular phase begins right at the beginning of menstruation and ends when you start to ovulate.

This phase is triggered when the hypothalamus sends signals to your pituitary gland to release follicle stimulating hormones (FSH). Your ovaries will produce 5-20 small sacs. Of all those sacs, one or two will survive to maturity while the rest of the sacs get reabsorbed into your body.

The maturing egg sets of estrogen in your body which causes the lining of your uterus to thicken for a potential embryo to grow.


Ovulation is the shortest phase of the menstrual cycle. It lasts anywhere from 16-32 hours. This is when a mature egg is released to the uterus. If fertilized, the body begins to prepare for pregnancy. If unfertilized, the body prepares for menstruation all over again.

Interestingly enough, some people claim to feel when this happens. They’ll usually feel a dull pain in their lower abdomen depending on which ovary releases the egg. No one knows precisely what causes this pain. But, if you’re one of the lucky ones to feel it, it does have an interesting name: mittelschmerz (literally ‘middle pain’).


This phase begins right after ovulation. After the mature egg is released from its follicle, the structure left is called the corpus luteum. Its primary function is to release hormones. Your estrogen and progesterone levels are surging. These hormone changes are to prepare the uterus for a potentially fertilized egg.

The endometrium thickens and fills with fluids. The cervix also thickens to prevent any bacteria from entering the uterus. Milk ducts in the breast also dilate.

Because of this, you may experience symptoms of premenstrual syndrome (PMS). The food cravings, mood swings, bloating, and breast tenderness definitely aren’t in your head. Your hormones are totally to blame here.

All this is to prepare for a potential embryo. But with no embryo, the cycle begins all over again.

Whew! The explanation for your body’s natural cycles is way more wordy than when it happens. But tell us, did you learn something about yourself? What surprised you the most? Tell us all about it in the comments below.

Next week, look out for when we tell you about a new way to be productive using your cycle. Is it even possible? Stay tuned and find out!

Sources: Stages of the Menstrual Cycle

Menstrual Cycle

Shop Ruby Love

Share Post