Would this be or not?

I am 23...newly single...so kinda over did it one night on drinking. I was with my best friends. Well on 09/25/09 I remember going to Ninfa's (a restaraunt) and had 2 margaritas. That is the last thing I remember. My best friend Anthony, told me we went to 2 other bars which I have no clue about. That I said I felt like I had to throw up and he literally picked me up like a baby and carried me to the bathroom. I woke up the next morning in Anthony's bed. Fully clothed so I wasn't worried. Yesterday he asked me if I remember that night and I said the last thing I remember is the 2 margaritas. Well he said we had ...which I have no recollection of. Apparently he knew I was incoherent if he had to carry me to the bath room. I asked him if he used protection and he said yes. I am supposed to start my period on October 4th. A few days ago, I bled...I thought I was on my period but that was it. No more blood. I have heard of implantation bleeding. Am I being paranoid??? Also, I know it was my fault for getting so drunk, but if I was not even coherent and didn't know what was going on but he did, is that considered ?