Plan B

So at one point I was on the pill. I stopped for about a month and a half maybe two to let my body clean it's self and what not. So I had unprotected sex with my boyfriend one day and he didnt pull out or anything because we completely forgot just being so caught up in the moment. As soon as we realized it ( which was once the moment was over ) i took plan b about thirty minutes later. ( meaning thirty minutes after the unprotected sex ) Then about 3 days to a week later I got my period. I guess at this point im just paranoid... do you guys think there is a chance the pill didnt work even though i took it so soon. I only ask because its about three weeks later and I feel like throwing up so im nervous!!!