About 4 weeks ago I had sex. We used a condom but I wasn't "wet" or anything and it was my first time. He acted WEIRD after he finished. Well I didn't think I was pregnant until I threw up the other day. I also got so dizzy BUT that was two weeks after sex. Well I took a pregnancy test at 2 weeks. Negative. Then again at 3 weeks. Negative. I threw up again 2 days ago. I also have been more moody.