A birth control app, not a period tracker

Can a period tracker know my fertility?

Keeping track of menstruation is an important part of our routines. It allows you to monitor patterns in your cycle and see how regular your bleeding or spotting is. We think it’s great that there are so many options for tracking periods.

That said, noting our menstruation dates alone cannot teach us all there is to know about our unique cycles. Menstrual cycles are sensitive and can change if we’re stressed, our diet alters, or we aren’t getting enough sleep. By simply tracking periods, we can observe the changes, but we can’t anticipate them. This is why — among other factors — period tracking apps should not be used to prevent pregnancy. While cycle trackers might give a prediction of the fertile window, an app that’s based on the rhythm method will give static predictions, which means you won’t know until the end of a cycle if the fertile window has shifted — making it too late to prevent a pregnancy.

How can I more accurately predict my fertile window?

Understanding when ovulation takes place in the cycle is a key part of identifying the fertile window. It’s possible to find ovulation by taking ovulation tests (these measure a surge of hormones in urine), or by charting basal body temperature to find the spike in temperature, which is also triggered by hormones and signifies ovulation has taken place. However, finding ovulation alone is not enough to prevent pregnancy. This is because of sperm survival — sperm can live for up to five days inside the female reproductive system, so having sex five days before ovulation puts you at risk of getting pregnant.

This is where Natural Cycles comes in. Our birth control app uses body temperature data, paired with a fertility algorithm which learns the pattern in your cycle, so it can predict and find ovulation from cycle to cycle. The app gives Green Days for days when you’re not fertile and Red Days when there is a risk of becoming pregnant. If the algorithm is ever in doubt, it errs on the side of caution and gives a Red Day. 

That window of caution is important. Recent research comparing Natural Cycles with common period tracking methods found pregnancy risk per cycle was up to 44 times higher with calendar-based methods than with digital contraception. When cycles were irregular, the risk increased further to 65 times higher.

Plan or prevent pregnancy with Natural Cycles

Natural Cycles is FDA-cleared in the United States and CE-marked in Europe for use as contraception. It’s the first app of its kind to be certified birth control. If you want to know more about our process for certification, check out the science behind our birth control effectiveness for details on the study of over 15,000 women that played a key role.

However, finding the fertile window is not only helpful for preventing pregnancy. Since there are only 6 days in any cycle when we can conceive, finding these accurately is important for planning a pregnancy, too. Another study compared Natural Cycles to calendar-based methods and found that Natural Cycles was able to find fertile days more accurately.

On top of finding the fertile window, using Natural Cycles offers unique insights into our own bodies and helps us find patterns in our cycles. Using the NC° app you can discover the regularity of your cycle, note recurring symptoms, and see your unique temperature curve from cycle to cycle. Our community of Cyclers – women who use the app around the world – often tell us the ways in which they have learned more about their bodies in their reviews of Natural Cycles. 

Take control of your fertility today 

Period tracking apps aren’t designed to prevent pregnancy. These wellness tools serve fundamentally different purposes than certified birth control methods. It’s important to understand your options when it comes to choosing contraception, and find a method that works for you. Settling for a period tracking app can put you at risk — take control of your fertility and get started with Natural Cycles today.