Could I be pregnant? Or is it all in my head?

Mele
I had sex with my bf unprotected. Woke up the next morning, and I swear my tummy feels like there is something in it? I feel like I could of conceieved! It's been two days now.... Was sitting on the bus, and I felt like there was a little buldge in my abdomen. Could it be possible that I am pregnant?!!!!