I have been playing dawnguard for a while now as a vampire lord and as always i tend to forget to feed from time to time. One day i was fast travelling to windhelm and when i got there i was unlucky to turn in to a blood-starved vampire. however none of the guard or citizens reacted or attacked me witch they would normally do. so i am guessing this must be some kind of bug/glitch?

Yeah it was the same with me actually, I was thinking the same thing.

Guards don't attack you at stage 4 vampirism..only if you turn into a Vampire Lord infront of them.

Not a glitch/bug.

okay they must have changed it then, thanks for info.

Yes it's not a bug. It was changed. It's even mentioned sometimes on the loading screen.

Yep, so you no longer have to worry about fast travelling anymore.

i swear do people not read these days

It's defenetely better this way