The calendar-tracking method, or rhythm method, is one way people monitor and record their periods, but it might not be the most accurate. That's according to a new study released Monday by the ...

Lindsey Ellefson is Lifehacker’s Features Editor. She currently covers study and productivity hacks, as well as household and digital decluttering, and oversees the freelancers on the sex and ...

The rhythm or calendar method is a natural approach to birth control. It requires a person to monitor their menstrual cycle and signals from the body to estimate when sex is least likely to result in ...

Oura has taken steps to validate the accuracy of its Fertile Window feature, using its smart ring in a study to prove its credentials as an ovulation detector. The research, conducted by in-house ...