Period tracking apps help you track your menstrual cycle, so you know when to expect your period. Click here to subscribe to our channel 👉🏽 They’re growing in popularity worldwide, with the three most popular ones racking up over 250 million downloads between them. But studies show that some women might also be using them to avoid getting pregnant. One of the apps, Natural Cycles, has been approved in the US to be used as a contraceptive. The company claims it is 93% effective at preventing pregnancies, when used perfectly. So why are more people turning to these apps? Are they safe to use as a contraceptive and what are the risks? Sexologist Rayka Kumru from Turkey explains why these period tracking apps are becoming so popular and the privacy concerns around using them. Dr Francesco Rampazzo, a lecturer in Demography at the University of Oxford, tells us more about where period tracking apps are getting the most downloads. 00:00 Coming up 00:16 Intro 01:00 What is a sexologist? 01:37 How the menstrual cycle works 02:51 How period apps work 04:10 Why people use period apps 05:39 A study into period app use 07:45 Are the apps designed for birth control? 08:33 Are they reliable as contraception? 11:24 Data privacy concerns 12:12 Should you use these apps? 12:53 Goodbyes Watch more episodes from What in the World here 👉🏽 Instagram: @bbcwhatintheworld Email: whatintheworld@ WhatsApp: +44 330 12 33 22 6 Presenter: Hannah Gelbart Producers: Chelsea Coates, Benita Barden and Emilia Jansson Video Journalist: Baldeep Chahal Editor: Harriet Oliver ---------------- This is the official BBC World Service YouTube channel. If you like what we do, you can also find us here: Instagram 👉🏽 Twitter 👉🏽 Facebook 👉🏽 BBC World Service website 👉🏽 Thanks for watching and subscribing! #BBCWorldService #WorldService #periods #periodtracker #contraception