I'm not quite a girl, last I checked, and my sister isn't (yet) on the pill and I've never had a girlfriend I've been (directly-in-contact) intimate with, so I can't say from first-hand evidence. Now I'm sounding like a Board of Studies Science syllabus. Moving on.
I could sound predictable, and say: Consult with your prescribing physician.
Or I could sound a bit more twenty-first century: Look up your specific medication name on Google, Wikipedia or medical and pharmacetial websites and see if there are known side-effects which match yours. Or post the name here, someone (like myself) might have a pharmacist for a mother and be able to look it up in medication information books.
Either way, it is probably best to talk to your prescribing physician, in case something is wrong. They might be able give you something more or suggest some other change or modify the brand/type/dose/medication or send you for some tests.