I'm not sure why he won't let you go at least until your EDD ... however, given your history of not going into labor on your own ... perhaps he thinks, why would this time be any different?
That said .. IMO, the risk of uterine rupture is moreso when you are induced into labor ... not when your body naturally goes into labor. My first, I went into labor and ended up with a c/s then my 2nd was a VBAC and my 3rd was a scheduled c/s. When I had my VBAC .. I told myself that if I didn't go into labor on my own, then I'd have a c/s.
Obviously, Drs. like to plan things .. and if he can go ahead and schedule your c/s .. that's what he's going to feel is 'best' for him .. does that make sense. I think you could try and schedule for closer to you EDD .. but obviously, there are risks if you go past you EDD and I'm sure he doesn't want that to happen. However, if the c/s is coming up soon .. your best bet would have been to change this a little bit ago?!
Just pray that you'll go into labor sooner!!!! That's my last suggestion. :-D
Good Luck!!! :-D