Fertility monitors are getting smarter all the time. Take Daysy for instance: it is an ovulation tracker that measures your basal temperature in 60 seconds and tells users whether they are fertile or not. It uses a smart algorithm to produce accurate results and has an app that gives users details about their cycle.
This ovulation tracker is Bluetooth enabled. It determines fertile and infertile phases and gives feedback through its lights. Its app can maintain a menstrual cycle calendar and track cervical mucus, intercourse, and other info.