Last month my boyfriend and I was fooling around and I'm not sure if he had precum inside of me but last month my period was 4 days late and wasn't normal at all this month I'm 12 days late. I'm normally on the 28 day rule no later then 30 days. I get headaches and only at night I get this feeling like I have to throw up but I can't, my stomach feels like I'm cramping and my period coming but it dont. I'm nervous, could I be?