Original photo by Max Charping

What can we learn from period tracking?

Nikki Lee
HCI & Design at UW
Published in
9 min readFeb 4, 2017


This is a three part series on period tracking, co-authored with Daniel Epstein, based on a study we completed at the University of Washington. Part 1 explains our research and discusses why and how people track their periods. Part 2 is a discussion about how we can use this information to design better period tracking tools. Part 3 is an exploration of what it’s like to study women’s health as a male researcher.

Tracking information about yourself is an increasingly important part of American life. People all over the country track their lives, from counting how many steps they take each day to writing down what they eat to recording all of their finances. Tracking our lives helps us change them, giving us a reliable path to self-improvement.

Researchers have found that almost 70% of adults in the US track at least one thing related to their health. Better and better tools for health tracking get released all the time, but product designers have paid little attention to women’s health issues over the years. For example, when Apple HealthKit launched in 2014 it didn’t give users a way to track their periods. Unsurprisingly, this sparked public outrage. Why would product designers ignore a feature that half the population would find useful?

Our team was surprised to find that there was also very little academic research about this topic. Researchers have been exploring how people track themselves for about a decade. And yet, the first time we looked we didn’t find a single paper about how people track their periods — one of the oldest and most widespread self-tracking behaviors.

We decided to fill that gap.

Many of the assumptions that researchers have made about self-tracking just don’t apply to period tracking. For example, researchers have found that one of the most common reasons that people track themselves is to achieve a personal goal or change their habits. That’s not particularly relevant to periods — or many other parts of physical and mental health that researchers and designers are just starting to explore.

Understanding how people think about tracking their period opens our minds and leads us to design better self-tracking tools for everyone.

How we did it

We gathered data from three sources for our study:

  1. We looked at reviews from the most reviewed smartphone apps in the marketplace, such as Clue, Glow, and P. Tracker. All in all, we read 2,000 different app reviews from the Apple App Store and Android Market.
  2. We posted a survey asking people why and how they track their periods, and how they feel about the tools that they use. We got responses from 687 people, who we recruited from our Facebook and Twitter networks and a post to the r/teenagers subreddit.
  3. We found survey participants who had unique experiences and talked to them in more detail. We did follow-up interviews with 12 survey participants who were part of a minority in our dataset (racial, gender, or sexual minorities), or had an otherwise unusual experience tracking (like a health issue). We did this to hear perspectives which might not have shown up in the rest of our data.

For each data source, we read through the information we’d collected, grouped what people said into themes, and looked for patterns across all the data sets. These patterns became our results (our full paper has more details on our methods).

If you want to know more about the survey we sent peope or the interview questions we asked them, you can find that information here. That link also has more details about the demographic makeup of our survey participants.

A note about ethics

We did this research with approval from the University of Washington ethical review board (IRB). We had to make special considerations to survey and interview both teenagers (13–18) and adults (18+). We specifically asked that we be allowed to interview teenagers without their parents’ consent. The topic of menstruation is difficult for some families to talk about, and we didn’t want teens to feel uncomfortable or unsafe. We we particularly worried that parents might make assumptions about their teenager’s behavior (such as whether or not they are sexually active).

A note about limitations

It’s worth noting our study did have some serious limitations. Our study demographics were highly influenced by recruiting participants over our own Facebook networks and on Reddit. This means we can’t make any broad statements about what percentage of Americans track their period in some certain way (let alone talking about people outside the US). When compared to the rest of the US, we had relatively few participants who were racial minorities, and our participants were more educated and of higher socioeconomic status.

We believe that there is more work to do to understand the experiences of people from other backgrounds.

We also paid far less attention to pregnancy and fertility. There are apps which specifically aim to help people who are pregnant or trying to become pregnant, such as Fertility Friend and Kindara. We focused less on those apps, and more on lifelong menstruation.

Why people track

We identified five main reasons why people track their periods (keep in mind that a person might have more than one reason for tracking):

  1. To be aware of how their body is doing
  2. To understand their body’s reactions to different phases of their cycle
  3. To be prepared
  4. To become pregnant
  5. To have better conversations with healthcare providers

For many of the people we spoke to, tracking their period felt like an obvious and essential activity. This is different from other types of self-tracking that researchers have studied. Unlike intentionally deciding to track physical activity or finances for self-improvement, people don’t give the decision to track their periods much thought.

“my mother just taught me [tracking] was the thing you did. I don’t think there was ever any real explanation for why.”

“I didn’t really think much about it. [tracking] was almost like a routine.”

Body Awareness

Many people in our study viewed tracking as a “general health check”, as one person said.

it’s a huge help in really getting to know your body.

Understanding Reactions

Others tracked to understand their body’s physical and emotional reactions at different phases of their menstrual cycle. For example, one person tracked to “guess if cramping is likely to get worse”. People also look at their own data to make sense of their physical and/or emotional state.

sometimes I’m really emotional and irrational and I can look at my tracker, see that my period is due in a week or less and chill out and realize I’m PMSing instead of having real feelings.

Being prepared

Many people track their periods to be prepared: “to predict when I will need pads and tampons.” People plan events around their cycle, from leisure activities to intimacy.

I can literally plan my vacations and excursions around my time

I also plan alone time with my husband based on when my period comes… i.e. hotels without kids”.

Becoming pregnant

When trying to become pregnant, participants often switched from basic methods (like tracking on paper or in their head) to more sophisticated apps.

when I was younger I used to just remember. When I started trying for a baby, it became important to know my fertile times.

Inform conversations with doctors

As a conversation starter on health, doctors often ask patients when their last period was. Some participants tracked so they didn’t seem clueless. Others used it to keep track to monitor whether there was anything unusual.

it’s great because it lets me record unusual symptoms and then I can remember them for my doctor visits.

How people track

We found six methods and tools people use to track their cycle:

  1. Smartphone apps
  2. Digital calendars
  3. Writing in paper diaries
  4. Following cues in their birth control
  5. Noticing symptoms (like physical sensitivity or cramps)
  6. Remembering

Some people also don’t track their period at all. Others use multiple methods simultaneously, or switch between different methods. The table below shows how common each method was among our survey participants.

A table showing the percentage of respondents in each age group who said that they used each tool. Overall, 47% of respondents used a phone app, 12% used a digital calendar, 8% used a paper calendar, 12% used their birth control, 7% cued off of early symptoms, 19% remembered, and 11% did not track at all.

Phone Apps

Almost half of the people who answered our survey used an app on their phone to track their period. For some people, finding an app was the first thing they thought of when they started tracking their period. Others switched to an as soon as they got a smartphone. We heard many people say that they liked features that apps have, like notifications that tell you when your period is coming.

my memory is awful, so I like keeping track using a dedicated app

I used to use a calendar when I was a teenager…, [I] started using the app soon after I got a smartphone

Digital Calendars

Some survey respondents used a calendar on their phone and/or computer to track their period. Most did this because they check their calendar a lot already, and it’s what they use to manage other life events.

I use Google Calendar for other appointments, so this made sense to keep everything tracked together.

Paper Diaries and Calendars

Some people use a paper diary or calendar to keep track, the same way that others use digital calendars. Some people preferred a paper system; others felt that switching to a digital system was just too much effort. People also told us that they’d learned the method from their parents, who started tracking before digital systems were available.

In the 90’s it was the only option. [I] got used to it. I’m too lazy to search for an app.

my mom uses this method and she recommended it to me.

Following Hormonal Birth Control

Hormonal birth control methods typically have “off” days without active hormones: days when you take a different-colored placebo pill, don’t take a pill at all, or remove an insert (like a NuvaRing). Depending on the type of birth control, the “off” days could come every month, or every few months. The people we talked to said that they tracked by noticing how many pills they had left, or followed the reminders they got for removing their insert.

when my pills are gone for the month, I know my period is coming.

the approach of the [placebo] brown pills signal the approach of my period.

Noticing Early Symptoms and Physical Changes

Some participants tracked their cycle by noticing physical or emotional changes which typically align with their period, such as bloating, breast soreness, irritability, or fatigue.

from the onset of soreness I give myself a few days, and then I’m on high alert.

I get depressed and moody a few days before I start… I am able to recognize these emotions as a period coming.


Others simply remembered when their last period occurred, either by counting the days or remembering what else was going on in their lives.

I just remember the date when my last period started and count ahead ~25–30 days

I try to remember what I was doing the day it started the prior month and extrapolate from there.

Not Keeping Track

Some people did not keep track it all. About a third of these participants do not have a period, and don’t have much reason to track. Some people kept supplies with them all the time. Others would often forget and be surprised by their period.

“[I] keep tampons at home and in my car all the time”

“I do nothing at all. It leads to quite a few ruined pairs of underwear.”

Why this matters

Research on self-tracking has historically focused on areas where people have some control over what they are tracking. Someone who is tracking their spending, their running, or their food can change their behavior in response to what they learn from tracking. However, when people track their period they are mainly observing what is happening to them. There aren’t many ways for them to control their cycle besides hormonal regulation (like hormonal birth control).

For most people, tracking their period is about adjusting their thoughts and behaviors — changing their reactions to their period instead of changing the period itself. This is important to think about as we build more self-tracking tools. For example, tools for tracking mental health issues like anxiety or depression shouldn’t assume that users feel in control of their mental and emotional state.

We were surprised and overwhelmed by the amount of interest this study received while we were collecting data. Many people (mostly women) reached out to us excited to talk about their experiences and complain about the tools available to them. The practice of tracking periods is widespread; it’s something that’s relevant to a huge portion of the human population for much of their lifetime. It’s clear that people haven’t had many opportunities to share these experiences. We hope that other researchers follow us in exploring how apps and other tools can support people whose experiences have been paid little attention in the past.

Check out part 2 of this series, where we discuss what this tells us about building a better period tracking app.


The research summarized here was completed at the University of Washington by Daniel Epstein, Nikki Lee, Jennifer Kang, Elena Agapie, Jessica Schroeder, and Laura Pina with feedback, mentorship, and advice from James Fogarty, Julie Kientz, and Sean Munson. This work has been conditionally accepted for publication at CHI 2017, a leading conference on human-computer interaction.

The original research publication, which includes additional content and references to many more relevant academic studies, can be read in full on Daniel Epstein’s website.



Nikki Lee
HCI & Design at UW

Designer, engineer, maker-of-things. Product manager building a better government at 18F.