Am i pregnant??????????????????????…

ok, ive had my last two periods since the "accident". they were both normal and then i went to the dr and got put on birth control because i was so scared i got pregnant. Anyways, i was talking to my friend about my situation and she was saying that you can have your period and still be pregnant. I would of been about 8 weeks if i were pregnant when i went to the dr. when she did the pelvic exam she would of felt if i were pregnant right? my uterus would of been bigger i hope.. does anyone know??? thanks!