I can appreciate the value of this Debian package to the fairer sex, but I have to admit the disclaimer is pretty amusing:
NOTE: This program is not a reliable contraceptive method. It does neither help to prevent sexual transmision diseases like AIDS. It is just an electronic means of keeping track of some of your medical data and extract some statistical conclusions from them. You cannot consider this program as a substitute for your gynecologist in any way. [emphasis mine]
I think if you’re the sort of person who would confuse a computer program with the Pill, a condom, or a gynecologist, the disclaimer really isn’t going to help you very much.