Am I pregnant or is my mind messing with me?!

Gabby
Okay I am wanting people's opinion on weather or not I could be pregnant?? 
I had sex on the 14th of August, he came inside of me twice, but I had my period on the 21-22nd. My period is usually 3 days long and heavy, but this time around I was 2 days late and my flow wasent that heavy and it was only 2 days which has never happened to me it's always been 3 days. I have also noticied that I have been feeling light headed, and more hungry. I don't have tender breast or nausea. Could I be pregnant or is it my mind messing with my head? Please help ladies!