my girlfriend takes depo provera and her periods are more often, because of that we rarely are able to have sex and when she finally isn't on her period she never seems up to it. In fact we haven't done anything sexual at all since valentine's day?

I'm not sure what you're stating the problem is.....are you/she concerned that her periods are frequent? If so, she needs to speak with her doctor regarding her birth control....which actually has many, and some terrible side effects.....(save her the side effects, use a condom) or, are you concerned with the no intimacy thing? If that's the case....if she's having her period frequently, she probably doesn't feel like it for one....again, we come back to hormones...birth control works by playing havoc with her hormones, and may be to blame for her lack of enthusiasm. Again, she needs to talk to her doctor and explain these symptoms, she might just need an adjustment in her type of birth control. Doctor can't fix what he/she doesn't know about.