Am I crazy, due on or possibly pregnant?!

Tara
Hey ladies, 
Please no negative or hurtful comments!! I am due my period next week, and we had unprotected sex twice last week, yesterday and today I've had slight niggling cramps not as harsh as period pains, sore/sensitive nipples, emotional and a slight nausea feeling before my morning coffee..... Am I going mad?! Could symptoms appear this soon?!?! With my first child I had no signs at all of pregnancy, my second I was sick and poorly throughout.... Please help or advice?!?
Many thanks xx