While periods and menstrual cycles are a regular and natural part of most women’s lives, very few people truly understand the different phases involved in a typical cycle or what’s going on inside your body during the four phases. In order to know whether you have a “healthy” or normal cycle, understand when you’re most likely to fall pregnant, and gain a good indication of whether your body is functioning optimally, it’s important to understand what’s involved in each menstrual cycle. So let’s dive into the details!

What is a “Normal” Cycle?

Good question! A menstrual cycle can look so different for each person. A typical menstrual cycle lasts, on average, for around 28 days. During this time, your body moves through four distinct stages, with different hormonal fluctuations occurring within each phase.

However, some women will experience longer or shorter cycles than the 28-day average. Further still, some will bleed for just 3 days of their cycle, while others will experience their monthly period for up to 8 days each month. Some women will only have light bleeding, while others endure a heavy flow. So when it comes to defining a “normal” cycle, it can be tricky. But there are certain indicators and phases which indicate your cycle is healthy and functioning as it should be – even if you fall slightly outside these averages.

The 4 Phases of Your Cycle

Day 1-7: Menstruation

The first phase of your cycle begins on the first day of your period. Your body recognises that an egg hasn’t been fertilised during your last cycle, responding by shedding your endometrium or your uterine lining, and the unfertilised egg along with it. This, of course, is your period. Your period can last up to 8 days, but most women average 5-6 days of bleeding. During your menstruation phase, your production of oestrogen and progesterone is at its lowest.

Day 7-14: Follicular Phase

The second phase of your cycle sees your production of follicle stimulating hormone (FSH) increase, signalling to your ovaries to prepare for ovulation. The rise in FSH communicates to your ovaries that it’s time to produce little follicles, each of which contains an immature egg. During each menstrual cycle, usually one dominant follicle will mature into an egg, producing oestrogen as it grows, and the remaining follicles will die off. While this is occurring, the lining of your uterus is also building up, in preparation for the implantation of the dominant follicle (or the egg) should you fall pregnant.

(Approximately) Day 14: Ovulation

Ovulation occurs approximately midway in your cycle.  For example, if a women experienced a 28-day cycle, ovulation would be calculated around 14 days before the start of the next menstrual period, making ovulation on (or around) day 14 of her cycle. 

During ovulation, you experience high levels of oestrogen (produced during the follicular phase), which trigger the release of gonadotrophin-releasing hormone (GnRH). GnRH signals to your body to simultaneously increase its production of luteinising hormone (LH) and FSH. Once your LH levels rise, ovulation will occur within 2 days, leading to the mature follicle/egg being released from the ovary, to travel to your fallopian tube. If pregnancy does occur, it does so in this tube.

Ovulation makes up a very short window of your menstrual cycle, and is (technically) the only time during which you’re fertile and able to conceive a baby. Your egg, once released, only survives for around 24 hours, so this period of time is crucial for those trying to fall pregnant. If there is no sperm present to fertilise the egg during the ovulation period, it will die.

Days 15-28: Luteal Phase

During the second half of your cycle, your oestrogen and progesterone production increases further, making your endometrium even thicker to allow an egg to be implanted (if it’s been fertilised).

From here, your cycle will take one of two routes. Firstly, in the event that the egg is fertilised, it goes on to implant into the uterine lining. Your body responds by producing a hormone called human chorionic gonadotrophin (HCG), as well as producing more and more progesterone to maintain the thickened uterine lining and support implantation of the egg.

If, however, the egg isn’t fertilised, and instead it dies (usually around day 22 of your cycle), your body realises there’s no need to maintain a thick endometrium lining, so it stops producing progesterone. After this happens, the uterine lining can no longer be maintained, so it begins to thin out and shed, resulting in your period.

How Many Days Is A Normal Period?

While a “normal” menstrual cycle averages around 28 days in total, the period or menstrual phase typically lasts between 3-8 days, with most women averaging 5 days of bleeding. However, it can take several years for your cycle to normalise when you first start menstruating. For the first few years of your period, you’re likely to experience longer cycles, though these often shorten as they normalise and as you get older.

Similarly, research has found only 13% of women ovulate on day 14 of their cycle, suggesting that very few women actually experience a cycle lasting exactly 28 days. So if your cycle is slightly longer or shorter than the average, don’t panic! You’re not alone.

If your cycle is significantly shorter than the 28 days, this could be owing to several factors, such as high stress levels, excessive oestrogen, low progesterone production (or all three).  It is also important to note, that younger girls just starting their period, or women approaching menopause, may experience shorter or lighter periods for this very reason as you are usually producing less oestrogen and progesterone during these phases of life.

On the other hand, if your cycle is significantly longer than 35 days, this may indicate it’s time for a general health check up. Long cycles can be linked to low body weight, too much exercise, eating disorders, not consuming enough food, or weight loss. It could also be down to various health conditions such as endometriosis, PCOS, miscarriage or hypothyroidism, or the result of a hormonal birth control overriding your natural hormone production and fluctuations. Don’t panic, it’s not an immediate cause for alarm, but it is worth having a check up.

What Are Premenstrual Symptoms? And When Do They Normally Occur?

The hormonal fluctuations occurring in the luteal phase of your cycle (between days 15-28) are responsible for premenstrual symptoms experienced by some women, such as headaches, bloating, nausea and cramping.
The most commonly experienced premenstrual symptoms include:
Abdominal cramps. These often hit a few days before your period begins, and can last for several days. You may experience mild, minor aches, while others will be struck by more severe, debilitating pain. Remember, extreme pain isn’t normal, and help and support are available to lessen the severity and symptoms you’re experiencing.

Abdominal bloating. Changes in your production of oestrogen and progesterone can cause your body to retain more water and salt than usual, making bloating one of the most commonly experienced premenstrual symptoms. Typically, this bloating eases within 2-3 days of your bleeding beginning.

Acne. Pre-period breakouts are common in the week leading up to your period – especially in those problem areas like your chin and jawline, which are closely linked to your hormone levels. You may also experience breakouts on your back, the rest of your face, or anywhere on your body.

Tiredness and fatigue. The sudden plummet in hormones which triggers the start of your period can also come with a side of severe tiredness or fatigue. This drop in hormones can also contribute to insomnia or difficulty sleeping, which of course worsens fatigue.

Headaches. Headaches can be triggered by the hormonal fluctuations leading up to, or in the first few days, of your period.

Moodiness. With your hormone levels all over the place, it’s no wonder many women experience mood swings or increased emotions during the days before your period begins.

Constipation or diarrhoea. Often you’ll experience some changes in your bowel movements right before (or during) your period, whether it be constipation, gas, nausea or diarrhoea.

Breast sensitivity. The fluctuations in your progesterone levels can cause some womens’ breasts to swell and become sore and aching in the days before your period begins.

Premenstrual symptoms are an early indicator that your period is on the way. However, if you’re experiencing severe or long-term symptoms, know that dealing with intense or ongoing pain is not normal! You deserve relief and support, and it’s important to work with a health professional to determine the cause of your suffering. There are many conditions such as endometriosis or PCOS which can exacerbate premenstrual symptoms, so it’s crucial you get the right help to ensure nothing sinister is going on for you. Plus, a medical professional will be able to advise you on how best to manage or reduce your pain and symptoms moving forwards – that’s reason enough to speak to a health practitioner!

What Do You Need To Know If You’re Trying To Conceive?

As mentioned, your “fertile window” during each cycle is actually much shorter than most people realise. You’re only fertile for the several days leading up to and during ovulation, after which the egg dies and is unable to be fertilised. Then, you remain unable to conceive until your next cycle (or ovulation phase).

However, if you’re not looking to conceive, this doesn’t mean the only time you need to use contraception or take action to prevent pregnancy is while you’re ovulating. It’s important to recognise that sperm can survive for several days in the fallopian tube! So while the egg only lives for a short while if it goes unfertilised, if you’ve had intercourse in the days prior to ovulation, there may still be living sperm hanging around in your fallopian tube waiting to fertilise any eggs that arrive there.

This is why choosing a reliable method of contraception you’ll be consistent with is so important. If you’re unsure what’s best for you, speak to a trusted health professional for guidance.

How Do You Know When You’re Ovulating?

To figure out when you’re ovulating, you first need to determine exactly how long your menstrual cycle is. Use a tracker, app or diary to keep track, noting down the first day you bleed as Day 1 of your cycle. The last day of your cycle is the day before your next period begins.

Once you’ve figured out how long your average cycle lasts for, all you need to know is that ovulation occurs around 14 days before your period begins. So, if you have a 28-day cycle, you’ll likely ovulate on around day 14. Or if your cycle is 35 days, you’ll be ovulating at approximately the day 21 mark.

Tracking your cycle is not always an accurate method to determine ovulation. Other important tools can be tracking your mood, body temperature, cervical mucus and position and testing your hormones through ovulation predictor kits (OPKs).

Given you’re most fertile in the three days leading up to ovulation, and while you’re ovulating, understanding when this is happening for you can be incredibly useful if you’re trying to conceive, or looking to avoid falling pregnant. Therefore, a combination of methods is most effective as cycles and patterns can change, so looking for patterns will help determine ovulation.

How Heavy Should Your Flow Be?

Most women tend to shed anywhere between 10-80 mL of blood and tissue throughout their period, with the average flow sitting at 35 mL. That looks like around 2-3 tablespoons of blood in total.

If you think you’re bleeding roughly this amount, this indicates your body is producing the right amount of progesterone, to allow your uterine lining to build up each month as you want it to. It’s a positive indicator of overall health.

On the other hand, if you’re experiencing a really light period, this could be a signal that your hormone levels are low or out of whack. You may need to make some lifestyle tweaks or changes to support a healthy cycle, including weight gain, increased food intake, reducing exercise and minimising stress where possible, depending on your body and what’s going on for you.

Or, if you think you’re bleeding far more than the 2-3 tablespoons each period, for example if you’re soaking through several tampons or pads each hour for several hours, or noticing big clots in your blood, this is a signal to speak to a health professional to make sure you’re not at risk of developing anaemia, or suffering from any health conditions.

Now you know your flow! Knowledge is power, so understanding what’s going on in your body, as well as useful indicators of health (or potential warning signs) allows you to keep track of your body, your fertility, and your menstrual cycle. This way, you have a better comprehension of how to conceive should that be something you hope to do now or in the future, or alternatively how to avoid falling pregnant. You’ll also be better able to identify any causes for concern in your cycle, and know when to seek help for severe premenstrual symptoms or undesirable cycle abnormalities and fluctuations.

Want to learn more, and work with a dietitian and health professional you can trust to optimise your cycle and your health? Get in touch today!