Chances are you just have a scratch in your throat that got worse from throwing up. I freaked out after throwing up blood, went to the er (this was about two weeks ago) and sat around for almost seven hours to be told its just my throat scratched. If you start to feel fluish, or get the shakes, go get checked out, but just take it easy for now and you should be good :)
Well I just threw up again for some reason and there is no blood now
Vomiting blood is never good. Pregnant or not. I'd call your doctor or go to the ER if I were you.