Help ! I’m scared !

I know it can totally be from my imagination, but I’m really really scared right now and I need to talk to someone.

My boyfriend and I had unprotected sex on Saturday 5-28. I expect my period on the 15th of this month. For the last 5 days I have bloating, and uncomfort in my upper stomach (the part between my breasts and my belly button). It seems to be larger and harder. I’ve got gas too :blush: I don’t know if it’s just my stomach or I can be pregnant ? I know for sure that my boyfriend have really really low sperm count, but still… If I’m really pregnant, how soon will I experience the symptoms ?