I had unprotected sex 9 times during my fertile time. I was about a week late for my period and took 4 HPTs all negative. I'm thinking maybe I was just too early?I googled implantation bleeding and it said that if I'm going to experience it, it'll happen on hte 5th week from the first day of my cycle, which is now.I got what I tought was my period yesterday, today is my second day. Usually the second day of my period id the heaviest day, but this apparent period is nearly gone. It's really really light to the point that I'm only wearing a panty liner. It doesnt look like a regular period either. I've had no cramping or anything with it either.Do you think the tests I took were just too early? And do you think that I'm possibly experiencing implantation bleeding?