What Causes Sudden Sharp Pain?

Hi, I was looking for information on Pulmonary Embolisms. There is something going on with me, and I don't want to rule out anything serious. I'm very young, and healthy (so far). If you get one, how long does it last? I read sudden death could occur, but.... how long after the pain sets in would that happen? I got a terrible sharp pain that lasted about 30 seconds, and since its been just a very very dull but constant pain.