A woman looking like she's trying to understand the menstrual cycle: the phases and hormones

There is more to your menstrual cycle than just your period!

What happens from period to period?

And, if your period ISN’T the main event of your menstrual cycle, what is?

Understanding your menstrual cycle better can be both fascinating and empowering as it holds the key to understanding your body better.  In this guide, we’ll unravel the complexities, simplifying the process into phases and hormonal events of the menstrual cycle. So, let’s dive in.

The Menstrual Cycle Begins

Your menstrual cycle starts from the first day of your period (heavy flow, not spotting) and lasts until the day before your next period. It is the time between one period and the next, that usually occurs monthly. Your period is just one event that happens in this cycle.

As a menstruating person, you will have approximately 450 of these menstrual cycles over your lifetime, from puberty to menopause (you heard that right, that’s 450 periods over your lifetime).

Menstrual cycles are USUALLY monthly, cyclical and predictable, so paying attention to your cycle will allow you to know when things are running as they should, and then when they are not. 

Debunking the 28-Day Menstrual Cycle Length Belief

In the realms of female biology, the average 28-day menstrual cycle has been long held as the gold standard, a sort of universal truth. We’ve all heard it – the idea that every menstrual cycle neatly fits into this convenient 28-day, month-long pattern. However, reality paints a far more diverse and complex picture.

In truth, menstrual cycles vary widely among menstruating people. A healthy menstrual cycle can range from 21 to 35 days. Some have shorter cycles, some longer. Some have regular cycles, while others experience irregularities. Regardless, of this variability, the menstrual cycle usually has 2 phases with 4 events. And as long as you’re gaining an understanding of your menstrual cycle phases and hormones that occur and how to identify these events via your fertility signs (more on that here) you can then embrace your own variability, individuality and be empowered with accurate information about your own body. 

Your menstrual cycle is a marvel orchestrated by various organs, systems, and hormones. Understanding this intricate dance involves acquainting yourself with the brain, ovaries, uterus, and key hormones such as:

  • Follicle Stimulating Hormone (FSH)
  • Luteinising Hormone (LH)
  • Oestrogen, and
  • Progesterone. 

For a refresh on the anatomy of your reproductive system including the brain, visit here.

Together, these organs, systems and hormones work together to help your body prepare for a potential pregnancy EVERY. SINGLE. CYCLE. (whether you want a baby right now, or not).

The Two Phases: 

  1. The Follicular Phase, and 
  2. The Luteal Phase

The Four Events: 

  1. The Period
  2. The Follicular Phase
  3. Ovulation, & 
  4. The Luteal Phase
a diagram representing the menstrual cycle, phases and hormone events that occur during the cycle

The Follicular Phase: Proliferative Phase of your Uterus – pre-ovulatory

  • Day 1: Your period begins, marking the start of your menstrual cycle. Day 1 is first day of your heavy bleed. Some can experience spotting, which is very light bleeding, usually a brownish or pinkish colour. This spotting is NOT the start of your period, but is actually considered part of your current or previous menstrual cycle. 
  • FSH Action: Follicle Stimulating Hormone (from your brain) stimulates your follicles to grow and mature. A follicle is a fluid filled sac that contains YOUR EGGS and each month 5 to 20 follicles will mature. These follicles produce the ever-so-important hormone, oestrogen. One of these follicles becomes the dominant and larger one and this dominant follicle stops the others from maturing. It is this dominant follicle that holds the egg that will be ovulated when the time is right.
  • Oestrogen the Dominant Hormone: Oestrogen thickens the uterine lining and prompts the cervix to produce cervical fluid.
  • Ovulation Trigger: When the oestrogen has been consistently high, it signals the brain telling it “here is an egg ready to ovulate” and the brain sends a surge of Luteinising Hormone (LH), which triggers the egg to burst out of the follicle and ovarian wall and this is what we call OVULATION or the MAIN EVENT.

The Luteal Phase: Secretory Phase of your Uterus – post-ovulatory

  • Corpus Luteum Formation: The egg travels down the fallopian tubes and the leftover follicle transforms into the Corpus Luteum. This gland is what will produce progesterone (and oestrogen) in the second phase (luteal phase) of your menstrual cycle.
  • Progesterone Reigns: Progesterone, alongside oestrogen, maintains the uterine lining for potential implantation. In the presence of progesterone, cervical fluid usually stops and a dry consistency returns. 
  • Pregnancy Possibility: If fertilisation occurs, the Corpus Luteum continues progesterone production, supporting early pregnancy. If not, the Corpus Luteum disintegrates, leading to hormonal decline, shedding the uterine lining, and initiating your period.

Just to recap and summaries each phase of your cycle, the dominant hormones and features:

Follicular phase: from period to ovulation

  • Period occurs
  • FSH stimulates follicles to grow
  • Oestrogen is the dominant hormone
  • Oestrogen reaches a threshold, causing the surge of LH
  • LH causes ovulation to occur

Luteal phase: from ovulation until the day before your period

  • Follicle becomes the corpus luteum
  • Corpus luteum produces progesterone and oestrogen
  • Progesterone is the dominant hormone
  • If no pregnancy occurs, corpus luteum disintegrates and hormone production declines

Why Understanding Your Menstrual Cycle Matters

  1. Empowering Knowledge: Understanding your menstrual cycle: the phases and hormones, empowers you with knowledge, allowing you to comprehend your body intricately. This allows you to understand your variability and individuality, which can assist with family planning (trying to conceive or avoiding a pregnancy) and/ or finding the underlying causes of irregularities. 
  2. Body Awareness: It enhances your awareness, enabling you to interpret your body’s signals, indicating both optimal and challenging phases. 
  3. Effective Tracking: With this information, you can start tracking your menstrual cycle. Tracking your cycle equips you to predict your period, understand your fertile window when trying to conceive, and make informed decisions about your reproductive health.

This knowledge empowers you, fosters body awareness, and facilitates mindful tracking, enabling you to live in harmony with your body’s natural cycles.

If you have any questions or thoughts, feel free to share them in the comments section. 

For those who grasp the concepts better visually, I invite you to explore my YouTube video titled “The Menstrual Cycle Explained.” This video compliments the information above, offering visual aids and diagrams to enhance your understanding of the theory presented. 

Happy learning!

Amanda xx