I have an app which lets me read all the twilight books. I thought i'd heard of them all but on the app theres the 4 main then theres midnight sun which is the beginning of the first twilight through Edwards eyes.
I don't think there will be another book. I read in an interview that S.Meyer found Twilight to not be a good place for her anymore. She was writing a book called Midnight Sun which is Twilight through Edward's eyes, but her draft was leaked and she hasn't written any more of it.