All content within this page has been reviewed and endorsed by
Dr Tariq Miskry, Consultant Gynaecologist & Obstetrician
But did you know that your menstrual cycle length isn’t always exactly one month long?
Like if you got your period on March 14, that doesn’t mean you’ll then get it on April 14, May 14, and June 14.
So, if it’s not a month, how many days are there in a menstrual cycle?
How many days are in a menstrual cycle?
The average menstrual cycle length is 28 days. But that’s just an average. Anywhere between 21 and 35 days is considered a normal menstrual cycle length.
Many women don’t notice it, but their menstrual cycle length can fluctuate slightly from month to month.
It turns out our bodies don’t always work on exact time schedules.
But how long is my cycle, you may be wondering. Knowing how many days there are in your period cycle is critical for calculating when your next period will come, which can be pretty important.
Getting caught off guard by your period is definitely no fun.
How to calculate your menstrual cycle?
Here’s how to figure out how many days are in your period cycle.
Mark when you got your period on a calendar. That is Day 1 of your menstrual cycle. From there, count each day until the day before your next period.
That’s how many days there are in your menstrual cycle.
So, if you got your next period on a Thursday, Wednesday would be the last day of your cycle. If you do this for a few months in a row, you can find the average number of days in your menstrual cycle – a.k.a your average menstrual cycle length.
Or, if you don’t feel like doing the maths, there are period calculator apps that do all this for you.
All you have to do is mark down when your period started and ended, and the app does the rest.
You can also use our online period calculator here:
Your period may be a little irregular when you first start menstruating, i.e. your menstrual cycle length won’t be uniform and predictable.
That’s normal. It takes your body a while to adjust to this whole new period thing.
But your menstrual cycle duration will typically normalize within a year.
Phases of your menstrual cycle
Though it may take some time for your normal menstrual cycle length to become predictable, a menstrual cycle is made up of four distinct phases, regardless of how long or short yours is.
First is menstruation. The first day of your period is actually Day 1 of your period, making menstruation – a.k.a getting your period – the first phase of your menstrual cycle.
This is when the lining of your uterus is shed, and comes out of your vagina as menstrual fluid, a mix of blood and tissue.
Next is what’s called the follicular phase, or pre-ovulation.
This is when one of your ovaries develops follicles, liquid filled sacs containing an egg.
One of these eggs will be released during ovulation – the next stage of your menstrual cycle.
Your ovaries take turns developing follicles. So, one month your left ovary develops follicles, while the next month your right ovary gets its turn, then your left in the month following, and so on. The lining of your uterus also thickens during this phase.
Ovulation is when your ovary releases a mature egg. The egg then travels down your fallopian tubes and into your uterus.
At this point, if your egg is fertilised by a male sperm, a baby will grow inside you.
How many days into your menstrual cycle ovulation occurs depends on your menstrual cycle duration.
It happens 14 days before the start of your next period.
For example, if you have a 28-day cycle, this means ovulation will occur 14 days after the first day of your period.
But if your menstrual cycle is just 22 days, you will ovulate only 8 days after the first day of your period.The last phase of your menstrual cycle is called the luteal phase, or pre-menstruation.
If your egg wasn’t fertilised, the lining of your uterus, also known as your endometrium in medical speak, will start to break down.
This is what can make some girls feel achy and crampy leading up to their period.
Getting ready for your period
Knowing when your period is on its way can come in very handy.
A few days before you expect your period to start, you may want to wear a pantyliner like Always Dailies.
Always Dailies protect your knickers from any spotting that you may get right before your period, as well as giving you a boost of freshness.
This way, you can be confident that you’ll never be caught off guard by your period.
Knowing how long your cycle is also lets you know when you’ll need to stash some extra Always Ultra pads in your bag or locker.
Always Ultra have a super absorbent core that keeps you up to 100% leak free and confident during your period. That’s a win!