I had unprotected sex with my boyfriend almost three weeks ago. The very next day, I started my period and about a week after that I began taking birth control pills. I've been having feeling like I have to throw up for the past week now. The first two times were early in the morning and the second time I actually did throw up. After that, I been experiencing nausea late at night. I take my pills in the afternoon with food so I don't see how it could take so long to make me sick. I'm wondering if I could have conceived before I started taking my pills. Could I be pregnant???