If you're using a method of contraception (birth control), and don't understand how it works, how about we use this spot to go ahead and ask and answer those questions here where everyone can benefit from them?
So, you don't get a method or a part of it, I'm happy to do some explaining right here.
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. - Margaret Mead