Phases of the menstrual cycle: Menstruation (your period)

grapefruit with a tampon

Have you ever wondered what is actually happening in your body every month during your cycle? Or how your periods happen? Periods and the menstrual cycle are discussed much more now than they ever used to be, but it can be very confusing. Over the next little while, we are going to talk about the different phases of the menstrual cycle and what happens in our bodies during each phase. Today we will start with menstruation (your period).

 

What is the menstrual cycle?

The menstrual cycle is the cycle of hormones that control our periods (and lots of other things in our bodies)

The main hormones involved are:

  • estrogen,
  • progesterone,
  • luteinizing hormone (LH) and
  • follicle stimulating hormone (FSH).

LH and FSH are produced in our brain and then travel through the blood to the ovaries. The ovaries produce estrogen and progesterone. The interaction between these hormones is what controls ovulation (when the ovaries release an egg) and our periods.

The menstrual cycle is what allows us to become pregnant. Our bodies “get ready” for a pregnancy each month and then if there is no pregnancy, we have our period and the cycle starts again.

Of course, contraception (birth control) interrupts this cycle. This is how it stops us from getting pregnant. We aren’t going to talk about contraception today but if you are interested then check out this article.

 

What are the different phases of our menstrual cycle?

The menstrual cycle can be divided in various ways. This depends on whether you are looking at what is happening in the uterus (womb) or the ovaries. The different names for the different phases can get very confusing and very ‘medical’ so we are going to try and avoid that.

Generally, the menstrual cycle can be divided into two halves:

  • the follicular phase and
  • the luteal phase.

There are also two ‘events’:

  • menstruation (your period) and
  • ovulation

It is very important to remember that everyone is different. There is a ‘textbook’ explanation of the menstrual cycle but not everyone will experience this. To explain the cycle I will use an example cycle that is 28 days long.

Any cycle between 21-35 days in length is considered ‘normal’. Some people have regular periods that occur at exactly the same time each month. Some people don’t. Everyone is different.

What matters is what is normal for you. Irregular periods (when you can’t predict when your period is going to start because it is random) might warrant talking to a doctor.

The diagram below shows what is happening during the different phases of the menstrual cycle. Along the top is what is happening in the ovary. The middle of the graph shows the hormones and the bottom is what is happening in the endometrium (lining of the uterus).

illustration of the menstrual cycle

 Source: Encyclopaedia Britannica

This article is focused on the first part (menstruation) of the first phase (follicular).

Period (Menstruation)

The first day of your period is day 1 of the menstrual cycle. This is the first day that you wake up bleeding. You then count the days of the cycle until the first day of your next period. Then you start again at 1.

How long is a period?

How long your period lasts will be unique to you. Anything up to 7 days of bleeding is considered ‘normal’. If you are bleeding for longer than 7 days with your periods then you may want to discuss this with a doctor – this article on heavy menstrual bleeding may also be helpful.

What happens during my period?

Hormonal changes

During your period most of the hormone levels are low but as your period progress FSH is increasing and estrogen is starting to increase. Progesterone and LH levels are low.

Physical changes (period symptoms)

Uterus

The endometrium (the lining of the uterus/womb) is being shed during the period. Your period is a mixture of blood and endometrial cells. This all falls away and then starts to build itself up again. And so the cycle continues.

Period pain is your uterus contracting

During your period your uterus contracts and relaxes. This is normal but in some people, it stays longer in the contracted state. This can cut off the oxygen supply to the uterus and cause pain (the same way that oxygen being cut off from the heart causes the pain associated with a heart attack). The coordination of contraction is controlled by chemical messengers called prostaglandins. We don’t really understand why some people have more prostaglandins than others and, therefore, why some people have painful periods and some don’t.

If you have period pain that is interfering with your life then talk to your healthcare professional about things that might help.

Ovaries

In the ovaries, the follicles (small bundles of cells that contain the egg) are starting to develop. The more they develop, the more estrogen they produce. Initially, lots of different follicles start to develop. Later on in the cycle one dominant follicle is “chosen” to keep developing while the others all stop.

Other physical changes

In addition to bleeding, some people experience other physical changes during their period. Symptoms such as nausea, crampy pain, headache, backache, or sore breasts can be common during your period. Feeling tired and lethargic is also common.

Psychological changes

Some people also experience psychological changes during their period. These might include feeling anxious or depressed. Feelings of anxiety or depression can be associated with physical symptoms such as period pain or exist on their own.

Equally, people with existing mental health concerns might find these get worse during their period. If this is an issue for you it is important to talk to your healthcare professional to ensure your treatment plan takes your menstrual cycle into account.

These mood changes can occur in the time leading up to the period (premenstrual) or during the period. The falling levels of estrogen and progesterone towards the end of the cycle (just before the period) can affect the chemicals in our brains that affect our moods, motivation, and sleep. Often people find that as the hormone levels rise with the beginning of the period their moods start to improve. For some people, the symptoms persist during their period.

 

How can I help my period symptoms?

If you are finding that your period symptoms are troubling you there are things you can do to help.

Sex and exercise for cramps and pain

Cramps/pain can be helped with rest or heat packs. Some people find that yoga or gentle exercise can help with the pain. Some people find that orgasm (either alone or with a partner) can help with period pain. Others don’t feel like having sex during their period and that is totally fine too.

Painkillers

If pain is severe then medicines such as paracetamol or ibuprofen can help. Always remember to check the packaging before starting any new medicines or ask your doctor if you are not sure. Doctors can also prescribe stronger pain relief for period pain if required.

There are lots of natural remedies that can help these symptoms as well.

If you feel you can exercise during your period this can also help with low mood or anxiety as well as pain.

Diet & lifestyle choices

It is always important to try and eat a balanced diet but this can be especially helpful for period symptoms. Trying to avoid too much sugar, salt, fat, alcohol and processed carbohydrates might help.

Getting enough sleep and mindful practices such as yoga or meditation can also be helpful. If you are finding your mood is troubling you a lot around your period it is important to speak to a medical professional who can help.

 

Can I get pregnant during my period?

Yes.

It is rare for someone to get pregnant during their period but it can happen. To get pregnant, there needs to be sperm in the vagina/uterus at the time of ovulation. But sperm can live for up to 7 days.  This means that if you have a short cycle then having sex during your period can lead to pregnancy. Remember you ovulate approximately 14 days before your next period starts. This means that if you have a cycle that is 21 days long (which is normal) then you ovulate around day 7. This means you could get pregnant during your period.

 

What next?

Hopefully, you now have a better idea of what is happening during the first few days of your cycle. Next time we will look at what happens next, during the rest of the follicular phase, before ovulation.


Disclaimer: This website does not provide medical advice
The information, including but not limited to, text, graphics, images and other material contained on this website are for informational purposes only. No material on this site is intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.

Posted By  : Katherine Maslowski

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About the author

Katherine Maslowski

Katherine Maslowski

Katherine is a junior doctor from New Zealand who has experience working in Obstetrics and Gynaecology and is currently studying an MSc in Women’s Health. She is passionate about women’s health and empowering women to learn about their bodies and understand how they work. She is particularly interested in sexual and reproductive health and helping women to make educated, informed choices about their health and wellbeing.

About the author

Katherine Maslowski

Katherine Maslowski

Katherine is a junior doctor from New Zealand who has experience working in Obstetrics and Gynaecology and is currently studying an MSc in Women’s Health. She is passionate about women’s health and empowering women to learn about their bodies and understand how they work. She is particularly interested in sexual and reproductive health and helping women to make educated, informed choices about their health and wellbeing.

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