I had had unprotected sex on my ovulation date, and i realized that only a day too late. Three days later i am having bleeding, much different than my period. this started out light, and drak brown, now the next day its a little heavier and bright red. However, my period should not have come for another 13 days. In anyones opinion could this be an implantation bleeding? I dont have to use more than one tampon a day, i dont have huge cramps like i would normally on my period.