... my period ended, I had unprotected sex. To be honest, my boyfriend and I were slightly intoxicated, but intoxicated nonetheless. Although he said he didn't finish at all, and he had pulled out as well, we still wanted to be safe and got plan b the next day (about 10-12 hours later). Exactly 7 seven days later I had heavy bleeding for three days (enough for a tampon; visible clots). I was due in a little over three weeks, if I go by my normal 30-day cycle from the day my last period ended. I'm now a week and slightly worried. I plan on visiting my doctor if doesn't start soon, but I was just wondering is it's possible that it's just the Morning After Pill at work? At most, how drastically can plan b actually throw off an individual?