menstrual cycle 101

The Menstrual Cycle Explained

Quick links to learn about your cycle:

Optimal Period Founder Natalie Brown mastering her menstrual cycle. Natalie is mid run and looking happy and empowered.

What is a regular menstrual cycle?

Length and regularity

Normal menstrual cycle length is 28 days. But, it’s normal for this to be anywhere between 21 and 35 days and up to 40days in adolescents.

Your menstrual cycle is the number of days from the first day of your period, all the way to your next period. That’s right, the menstrual cycle is not just the period – it is a repeating pattern of fluctuating hormones.

Hormones - what you need to know

Hormones are your bodies messaging system; hormones travel in the bloodstream around your body.

The main hormones controlling the menstrual cycle are oestrogen and progesterone. These are released from the reproductive system because of 2 controlling hormones produced in the brain (follicle stimulating hormone and lutenising hormone for those that want to know!)

These 2 hormones send messages to the reproductive system to prepare and release an egg (ovary – ovulation) about halfway through your menstrual cycle. Alongside this, the hormones cause your uterus lining to build up just in case fertilisation occurs (pregnancy). If this doesn’t happen, your body sends more hormone messages to the reproductive system to shed the uterus lining which has built up. If pregnancy doesn’t occur, you don’t need this lining = this is your period.

A regular menstrual cycle is super important, it is an extra vital sign of health. A regular menstrual cycle indicates a good energy balance and that the body’s hormones and reproductive system are working well.

STOP! Irregular menstrual cycles or periods should not be ignored, if you haven’t had a natural menstrual cycle (and not using hormonal contraceptives) for 3 months or more, seek medical advice. For information on what to ask your doctor. You can also visit our free resources page.

Sign-up to receive the latest info delivered straight to you.

You will receive updates as we release new information (hot off the research press!) to help you manage those period symptoms and keep performing at your best. Don’t miss out on the opportunity to join workshops, discuss common symptoms and be part of our community sharing ways to improve and manage your menstrual cycles.

What are the stages of the menstrual cycle?

Your menstrual cycle can be split into different stages, or phases, based on the events happening and your hormone levels. As you can see in the image below, there are lots of ups and downs throughout the cycle, no wonder it’s normal to experience different symptoms.

The menstrual cycle can be split into these phases...

The early follicular phase, the time you are bleeding which normally lasts 3-7 days. Day 1 of your period is your menstrual cycle day 1.

The late follicular phase, there is a huge increase in oestrogen in the lead up to ovulation which occurs approximately midway through your cycle.

The mid luteal phase, after ovulation there is a second peak in oestrogen and progesterone rises, reaching a peak to prepare the uterus lining

The late luteal phase, in the absence of fertilisation, both progesterone and oestrogen drop rapidly and the uterus lining breaks down which results in your period…back to day 1 of the early follicular phase.

Why do we need to know about these phases? 

Well, different symptoms both positive and negative occur within these phases. This is the first step to understanding which symptoms you experience and at what phase of your menstrual cycle. This can help you determine if your menstrual cycle is causing those symptoms or if its ‘life symptoms’ instead.

Menstrual cycle diagram


Struggling with symptoms. Let’s explore the most common menstrual-related symptoms and when you might experience them

Early follicular phase – bleeding, stomach cramps, back pain, sleep disturbance

Late follicular phase – lets go get them girl, confident, motivated, energetic, strong, focussed, ready to take a risk or have that challenging conversation

Mid luteal phase – bloating, gastrointestinal disturbance (constipation or diarrhoea), temperature increase, bloating, weight changes, food cravings, reduced coordination. Good time for planning.

Late luteal phase – all of the above PLUS headaches, irritability, decreased energy levels/lethargic, reduced motivation, ill/cold symptoms, sleep disturbance, tired, dizzy, worry/anxiety, emotional, poor core control, mood swings.

STOP! Although these symptoms are all super common, they should not be debilitating or stop anyone completing daily activities. If they do seek medical advice.

Woman dancing, feeling happy and free after mastering her menstrual cycle

Want to start understanding YOUR menstrual cycle?

Visit our bank of free resources to get started.

All information is based on research.  However, we are not medical doctors at Optimal period (PhD Dr’s instead!), for any medical advice please speak to your medical practitioner.