Confused about your menstrual cycle? Worried about calculating your ovulation date? Got questions about your menstrual cycle? This post is for you. Happy reading, and don’t forget to share this knowledge with your community.

One can’t entirely capture women’s health without discussing the menstrual cycle. As humans, one significant differentiating factor between the man and woman sex is our reproductive systems. For the woman, the menstrual cycle is the centre of her health. I like to say that the menstrual cycle is the woman’s health checklist. Every stage or period in the cycle has its significance and any derangement is a pointer to an underlying disease or condition.

It’s also worthy of note that the menstrual cycle is significant from woman to woman. No two women have the exact menstrual cycle. While there may be similarities in cycle lengths, there maybe differences in flow patterns and intensities. This is why the scope of what medical science considers normal, is in ranges, not definite numbers.

Short answer, you cannot tell if anything is wrong… if you do not know what’s right. Ignorance of your normal pattern will either leave you panicking when there’s nothing wrong, relaxed when there’s something wrong, or just confused . And all these states can end badly if handled wrongly. A sound basic knowledge of one’s cycle can help with early detection of many Gynaecological diseases. Early detection, we always say, is key to early treatment and good outcomes. If ever in doubt, best to speak to a healthcare professional who will guide you towards making the right call.

What is a Menstrual Cycle?

In basic terms, this is a hormonal process, a woman’s body (starting from the uterus and ovaries) goes through every month in preparation for possible pregnancy. This occurs between puberty and menopause. Series of hormones are produced to facilitate the maturation and release of an egg in preparation for possible fertilization by a sperm cell, this is called Ovulation. In the absence of fertilization, the egg is shed together with the uterine lining (which was thickened and enriched with blood vessels in
preparation for potential implantation), out of the vagina. This shedding lasts for a number of days. This is called Menstruation and depending on how thick and vascularized the uterine lining was in preparation for implantation, the period is characterized as heavy or light. After the shedding, the cycle continues like that for every month in a woman’s life, until intervals when pregnancy occurs or menopause commences. This is the summary of the menstrual cycle.

Important Menstrual Cycle Dates to Note


This is simply the term that describes the first time (age) a young adolescent girl sees her period. While this may seem trivial, knowing the age of one’s menstrual debut comes in handy in diagnosing certain gynaecological diseases in the future
Some of these include hormonal disorders, infertility and even certain oestrogen dependent cancers.
I’ll give you an instance:
Long oestrogen exposure is implicated in breast cancers. So the longer a woman is exposed to the female hormone, oestrogen, the more her chances of having breast cancer (in the prescence of other risk factors). Exposure to oestrogen (which is normal), happens from “menarche” to “menopause”. The exposure is only interrupted by pregnancy and lactation which both suppress oestrogen. This means a woman whose menarche was at 12 and menopause at 50 (38 years of menstruation) is more exposed to oestrogen, compared to a woman whose menarche was at 16 but menopause at 50 (34 years of menstruation).
Normal menarche range: Ages 10-16. In some young girls with precocious puberty (premature or very early puberty), they could menstruate from as early as 7 or 8 years. This could be genetic, due to some underlying medical conditions, obesity or even be associated with exposure to sex hormones like oestrogen. See a Doctor to rule out any pathology.


This is the age when a woman sees her period for the final time. According to a post by Cleveland Clinic, during menopause, the ovaries no longer release eggs and estrogen levels become very low. Once a woman has not had periods for 12 straight months, she has gone through menopause. However, it is important to ensure that the lack of periods is not due to another reason (like abnormal thyroid function or the use of birth control pills).

Normal range: 50-55 years

Premature menopause: Before age 40

Early menopause: 40-45 years
A premature menopause could be due to a positive family history (genes), medical intervention, like a hysterectomy ( removal of uterus) or oophorectomy – removal of ovaries, as treatment options. It could also be a side effect of prolonged exposure to chemotherapy or radiation (cancer therapy). Some auto immune diseases are also implicated. In some women, the cause of early menopause is unknown.

Period Cycle length.

As a woman, your menstrual cycle commences from day one of your period. The cycle length is simply the interval between day one of your current menstruation, to day one of the next menstruation.

Normal range: 21-35 days.
This means that any cycle length below 21 days or above 35 days is considered abnormal until proven otherwise.

It is worthy of note that a woman’s cycle changes several times in her lifetime. Several factors can influence this, from stress, to environmental changes, dietary changes, underlying medical disorders, hormonal imbalances etc. It may be nothing to worry about, however if these changes give you concern, then talk to your gynaecologist.

Here’s a simple way to calculate your period:

In your calendar. Note down, or circle the first day of your period this month. Then next month, circle the first day of the next period. Count the days from day one, to the next day one. Do these over 6-12 months to understand your cycle length better. It’s that easy. There are also some apps available to help you keep track of your cycle, a good one is the FLO app. However, it always helps to have a foundational knowledge of your menstrual cycle, for days when technology fails.

Period Flow

This speaks of the duration of a woman’s period. How long does your period last when it visits? This is equally important.
Normal range: 2-7 days.
Any flow below 2 days Or above 7 days is considered abnormal until proven otherwise by a physician.

Period Flow intensity:

Heavy or light flow? A woman’s period could be light, moderate or heavy. Heavy flows could be pointers to an underlying Gynaecological issue. Fibroids, endometriosis and some other uterine conditions could cause one to have very heavy menstrual bleeding, which might require medical intervention.


Period cramps are characterized by uncomfortable to distressing pelvic pain. They can be mild, moderate or severe. Asides cramps, other menstrual symptoms exist, like nausea, vomiting, headaches, dizziness, drowsiness, period diarrhea, constipation, bloating, breast tenderness, mood swings, etc. These vary from woman to woman. Learn more about Premenstrual Syndrome (PMS) here.

It is possible and normal too for a woman to feel no pain or cramps during her period.

It is important to note the intensity of pain experienced during one’s period, cos while the mild to moderate cramps may be insignificant, debilitating pain isn’t. Any menstrual cramp or pain that interferes with one’s normal daily activities, is called DYSMENORRHEA and should be treated seriously. Dysmenorrhea may be physiological, it could also be a pointer to a more severe underlying Gynaecological condition. Some possible causes of dysmenorrhea include: Fibroids, Endometriosis, Adenomyosis, Pelvic Inflammatory Disease.


This is simply the period when a woman releases eggs from the ovary, which await fertilization from a sperm cell. It is the period when she is most likely to get pregnant if she has unprotected sex.

This duration isn’t fixed. It varies from woman to woman. To know one’s ovulation period, one must understand her cycle length.
Determine your cycle length.
Subtract 14 days from it. Add + or – 2 (Plus or minus 2 days). That’s your ovulation day range. This means, your ovulation can fall on any of those cycle days in a month.
Note that, it is not calendar dates, but cycle days.

E.g: Ada has a cycle length of 30 days. She subtracts 14 from it. 30-14 is 16. This means Ada’s ovulation day is “Day 16” of her menstrual cycle. To get her range, age adds 2 and also subtracts 2 from 16.
Range = 16-2 to 16+2. Day 14- Day 18 is her ovulation day range. By range it means, her ovulation day can vary month to month but within any of these days. It could be Day 15 in January, Day 17 in February, Day 14 in March, Day 16 in April.

Note: The sperm cell has the ability to live up to 3-5 days in the uterus awaiting fertilization. This means having sex 5 days before ovulation is also likely to get a woman pregnant. A woman’s fertile window is 5 days before her ovulation till a day after her ovulation, ^ days in total.
If you’re trying to avoid pregnancy while having unprotected sex, or even trying to get pregnant, this should be very helpful.
So for Ada used in the example above, her fertile window is 5 days before day 14 and a day after day 18. Thanks to technology, using an ovulation tracker can however help a woman know her definite ovulation date in a month.

Ovulation precedes menstruation, so a woman who doesn’t ovulate isn’t likely to menstruate. Ovulation also comes with a slight cramping in women called “Mittelschmerz”. It is a sign of ovulation in women. Other signs of ovulation will be discussed in another blog post. Stay connected.

Here are facts to note!

1) Understand that your cycle is an average. It might fluctuate between a number of days, but you’ll find the average menstrual cycle within 6-12months of monitoring it. E.g: It might fluctuate between Day 30, 29, and 31. But is mostly 30.

2) Note that many things can cause your cycle length to shift from your normal and as long as it is within a normal range, there’s no cause for alarm. If worried, please see your Doctor.

3) Women with cycle lengths 28 and below, have a high likelihood of seeing their period twice in a month. At the beginning and at the end. This is normal.

4) It’s unreliable to calculate your cycle length with dates. Count days instead. That it came out 27th May, doesn’t mean it will come out 27th June. Count days, not dates.

A period below 21 or above 35 days, might be a cause for concern. I’ll advice you see a Doctor if this is always the case for you. A doctor will examine you and advise you better.

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6 Responses

  1. This is so insightful and helpful. Will be back to re-read for further digestion. They Dr☺️

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