Could I be pregnant?

Hi, I had unprotected sex during my period and he didn't come inside me as far as I know. Its been exactly 10 weeks and I'm feeling tired and sleepy all the time. I'm also having some very slight nausea that sometimes goes away. I've had my period twice since and it has been shorter and lighter than normal. The first lasted 4 days and the second  lasted only 3 days. Though feeling silly asking, is there a possibility that I could be pregnant? If i am pregnant, how far along would I be?