Am I Pregnant? Shortened period.

Patient: Okay, so I had more than usual sex on Friday the 2nd, protected of course and got my period the next Morning, it was suppose to be coming around that time and it was my normal flow very red and medium maybe even a littlemore than medium of a flow, I had it all day and the next day in the morning I took a shower and it stopped. it didn’t come back like it usually does. I’m been exercising a lot more lately and I’ve also been stressed. the thing is though I still where a tampon incase and I have the dark brown discharge I usually get when my period is ending. am I pregnant? what’s happening?

Symptoms: no symptoms