Pregnant?

My boyfriend and I had unprotected sex all though Novemeber. He pulled out but I know it's not 100% effective. He came inside me once and we used the morning after pill. That was on November 30th. I got my period on the 5th of December. Is there anyway I could be pregnant? I should be starting my period any days now. But, I'm really nervious because I have been feeling super weird. My stomach is expanded and I've gained weight but my eating habits have stayed the same.