Sorry, boy geeks, the Website of the Day does not apply to you today. Mon.thly.Info is a free service that tracks your menstrual cycle. Can I be real with you? Like really, real? I was a little turned off when I first read the description, but the fact that the interface is totally simple (and, um, completely adorable), I changed my mind.
You input a couple important dates, and Mon.thly predicts when your cycle will start again and will even email you when you should, uh, expect things to happen. Hey, sometimes we get busy and can't keep track of these things!