I'm supposed to get my period on the 20th give of take. I've been having unprotected intercourse throughout the month and on weeks where I might have been ovulating. On the 13(week before expected period) I bled light pinkish. Not a lot but enough to notice. I checked if I kept bleeding but it had stopped. I usually don't bleed before getting my period. Is it possible that it was implanation bleeding? Besides this I've been getting a few cramps & tender breasts& frequent urination (common PMS symptoms I get)