You're listening to Shortwave from NPR.

Today, I want to talk about someone, someone special, who's been knocking down my door every month since the sixth grade.

My period.

I got my period way before my friends.

It was a nightmare, but thankfully I had my mom around.

She even gave me a gift, this hardcover book, which was like an illustrated version of the Leanne Womack song.

I hope you dance.

I think it was her saying, you're becoming a woman now, and I was really mortified.

But mom also taught me this useful trick for period tracking, and like taking ownership over your cycle.

Which was to mark my calendar with red dots.

The dots would get a little bigger, the heavier the flow got, and then a little smaller.

When I was near the end of my period.

My head a very similar story.

My mom always drew a red line in her calendar and taught me to do the same, because we carried around physical planners when I was in high school.

Andrea Ford is a health data researcher at the University of Edinburgh.

And she's been collaborating with another researcher there, Julia Duttoni.

I was really bad at tracking my period.

I kept missing the date. I also had a physical planner when I was at school, so I did use my diary.

But then sometime I would forget, and it was always a surprise.

Oh, now it has arrived.

But six years ago, I started using period tracking apps in 2015.

And since then, I have to say, I know how to better schedule my meeting, appointment, holidays.

...