Me and my boyfriend had sex about 2 or 3 days ago and now I'm always running to the bathroom to pee but most the time I don't have to. I wake up feeling sick and certain foods make me nauseated. Today I started what I thought would be my period but it is very light and hardly anything. I was on birth control but missed a day and took 2 the next but then missed again an we had sex that day! Could I be pregnant?