Period is a week Early

So, it's been almost a year TTC and no luck. Well my husband and I actually had unplanned intercourse twice in a week during my ovulation. With that being said. For the past two weeks I've had off and on sore breasts and some cramping. This morning after 9-12 days after intercourse I woke up to some bleeding. It was brown the first wipe, then the second wipe was more of a pink or light red. I figured I started but thought how could I, I still have a week to go. So, I don't know what to think, 2 days ago I took a hpt and it was a BFN! What is going on?! I've read about Implantation Bleeding and is says I wouldn't have sore breasts or cramping. I tired of getting my hopes up...