Bleeding from sex - what is causing this? LADIES ONLY!?

Here's my question:

I was off of birth control for 3 months because my fiance was doing biology research in South Africa, and then got back on it (Aviane) in November when he returned. I have only rarely bled from sex with him, but for the past couple weeks I've been bleeding almost every time we do - just really really light. Its hardly any blood at all, but there is some. We don't have rough sex, so I don't understand what could be causing this. I am 100% positive that neither of us have any STDs, and he didn't hook up with anyone while abroad, so that's not a factor.

My period was also really weird this month - I got it at the time I was supposed to, based on the birth control pills, but it only lasted for one day, and then one day of extremely light spotting.

Does anyone have an idea of what could be going on? Thank you. I know I need to go see a doctor, and am going to make an appointment asap, but in the mean time I'm kind of worried.


Thanks!