From the phone and Windows apps, you can log your menstrual cycle start and end dates, as well as symptoms like headaches, acne and cramps. Fitbit will predict your upcoming cycles using its "proprietary cycle algorithm that gets smarter and more accurate as they log their period." Most women who've used any number of dedicated period or fertility apps will know that this is pretty standard fare for such a feature. What's different here is being able to see that in relation to other metrics that Fitbit already tracks, like sleep, weight and activity trends.

The app will also push general information about menstrual cycles, ovulation, fertility and common misconceptions from the company's blog. In the Community tab, Fitbit also added a section of groups for women to discuss topics like birth control, pregnancy and menopause.

On the watch, you'll find this information in the Fitbit Today dashboard by swiping up from the home screen. There, you can see where you are in your cycle, when your next period is expected and check your estimated fertile windows.