What happens if I throw up during my exam ?

I havent been feeling well the last couple days and I have an exam tomorrow afternoon. All this evening I've been fighting the urge to throw up. I really dont want to miss the exam and get a doctors note.

What will happen if I throw up during my exam? Hypothetically like onto my exam booklet or onto the floor? Do I just keep on writing ? Do they take me outside ? Do I rewrite? Has this happened to anyone before ??

UPDATE

Thanks for all the support guys, I just wrote the exam anyways, didnt puke - :))