I accidently pulled my trigger on my gun while clicking a door and now every five seconds it shoots. I have tried changing weapons nothing works.

Have you tried restarting the game? I've had this happen in FO3 a couple of times too after reloading a save in combat situations.

Ah the auto fire glitch

It happen to me after I died "I was shooting the gun at the time" when the game reloads your last save

For some reason the game think your pressing and holding the fire button down

I remember this happening once or twice on Fallout 3