Okay I've been on the depo shot since June of 07. I was put on some medicine to get rid of a bacteria in my espohgas that effected my birth control and made me bleed ever since. My boyfriend ejaculated inside me could I be pregnant?

If the medicine affected your birth control it made have made it so that it was not, in essence, "working", so yes, it is possible. If you are not sure about the effectiveness of your birth control, do not hesitate to use a second form of birth control like a condom, for added safety.