Have you ever gone to the doctor's office and been asked "when was your last period" or "how long are your menstrual cycles," and not known the answer?

That used to be me. I couldn't tell you when my last period was, how regular my cycle was or when to expect my next period to show up.

Today I wanted to share a simple way to count your menstrual cycle length to help you determine when you can expect your next period.

Now, this isn't foolproof, but if you're just using it to get a rough estimate of your period cycle length or when to expect your next period this will suffice.

Later in this post, I'll share what you need to learn in order to get super specific and be able to pinpoint different parts of your cycle and know within a few days when your period will arrive.

If you've never paid attention to when you have your period or marked anything on a calendar this will take a few months but will benefit you, in the long run, to start charting your cycle and periods.

So, what you're going to need to know is what day your period starts. Mark that on your calendar, or use an app like:

+ Kindara (free)

+ Read Your Body (14.99/year)

Those are my favorite cycle charting apps.

There are countless options in the app store if you search "period tracker" like Flo and Clue.

The day you start your period is Day 1 of that cycle.

You want to do this for at least three periods (menstrual cycles) to calculate the average length of your cycle. So you'll have four periods total marked on your calendar or app.

From there you add up the three cycle lengths. For example, let's look at my most recent periods to calculate my average cycle length.

Period 1 started January 25th

Period 2 started February 21st (27-day cycle)

Period 3 started March 18th (25-day cycle)

Period 4 started April 12th (25-day cycle)

Adding those three cycle lengths up I get 77 days.

Divide that by the number of cycles (3) and I get 25.6, rounded up to 26.

The more cycles you're able to add to the equation the better. Over the past 10 cycles I've had anywhere from 24 day cycles to 28 day cycles but my average is still 25.7, rounded up to 26.

So I'm able to mark on my calendar when to expect my periods, within a few days.

But I go even further, using the Sympto-Thermal Method of FAM to chart my basal body temperature and cervical fluid to know exactly where I am in my cycle (which phase), how fertile I am, when ovulation is approaching and I'm able to confirm ovulation

There are rules and guidelines to this method that make it a very effective birth control method (on par with the pill, 99.6% effective) when used correctly.

If you want to learn more about charting, FAM and using the sympto-thermal method as a natural form of birth control, check out my course, Chart Your Cycle.

Chart Your Cycle