As far as I know, the Gp B strep may be gone by the time you go into labour. Being pos now doesn't mean that you will be later, but I am not 100 per cent sure.
On the thrush side, I have used Canesten (inserted with finger not the applicator) in pregnancy (two actually) with the okay from GPs so you could check that?
And what about the Inner Health stuff- they may be stronger probiotics than what you are taking?
Just some ideas!