So I'm on BC pill, and about a week ago, my boyfriend and I had sex for the first time (my first time ever). I was on the 3rd day of my period, so I was taking the little sugar pills. We used a condom and he pulled out a good 5-7 mins before he came. This week, I've been feeling a little sick to my stomach and have had some constipation. I've read that morning sickness could start as early as one week. What's the possibility that I could be pregnant?