While having sex i penetrated my girl friend without a condom. I realized it after a couple of strokes and then immediately put on the condom. We were scared that she might get pregnant due to precum. So she took a contraceptive pill (I-pill) within 48 hours. This is the first time she ever took a contraceptive pill. We had sex again a week after and used protection. The next day she started bleeding heavily accompanied by mild abdominal pain. She has had irregular period and we don't know weather this has something to do with sex or she has her period. Moreover she just had her period 3 weeks ago. Can it also be the side affect of the contraceptive pill?