Early periods or could be pregnancy?

Hello everyone, I had unprotected sex 2weeks back and then, started feeling tired, crampy, moody And also my boobs hurts alot. Yesterday night I couldn't even sleep because of boobs were hurting very badly. But, in the morning I started having period like flow so, I assumed I am not preggy this time. But, weird thingis that it's almost gone by now. I am wondering is it was period at all? I was not due uphill nex week. Please help!