I tested postive to GBS with my first pregnancy (at the 36 week test) then I tested again the next appointment (38 weeks) and it came back negative....they still put me on the drip once I came into hospital in labour though, just to be sure. Very strange your Ob. already considers you GBS. Perhaps he's just adding that as a reason not to (really) support a VBAC.

There are things you can do to prevent being GBS (can't find the link though).

Given you changed from public to private I would suggest you find a more supportive Ob. I assume his VBAC stats are dismal, given his 'exception to the rule' comment. That's so not encouraging for you to hear so if you're willing to pay good money for a good Ob., well, I'd be looking elsewhere personally!

For what it's worth my second pregnancy was GBS negative, so it's not like once GBS pos, always GBS pos.