Okay so here is the story. I always have very heavy to medium periods. Last time I had sex we used condoms and went 'bareback', but I made sure that it was after my ovulation day. I cleaned up inside and outside afterwards just to get anything that might have stayed up there out. And like normal I had sore breasts, and very light cramps the week before my period. So, my period came (on time) but it wasn't like normal. It just much lighter than usual. Sometimes its very vibrant red, other times its brown, but i think it is just because i wear my tampon for long amounts of time ( i know i know don't yell). I even experienced a small clot once too. I've been reading about " implantation bleeding" but some aspect seem like it, and others don't. All day (day 6 of my light period) it smells very gross when i change my tampon. I also recently started running to train for a 5k so i don't know if exercising is the cause of this happening. Yesterday (day 5 of my light period) I took a pregnancy test and it came out "negative". My period seems to be lasting the right amount of time as usual. It's all so confusing, if anyone can explain that'd be great!