Any chances i concieved? ?

I had with my fiance and yes he came inside.. two days later i got my period though. It wasn't light, but not heavy either. ..And i wasn't in pain during it like usual. And the red blood only lasted like two and a half days.. the rest was brown. ..In addition, my periods always come at different times.. so they aren't regular. ..It's been a little over a week since that period and i'm having cramping and major mood swings.. Any opinions?