All of the other people above are correct; having Group B Strep at the start of pregnancy is no guarantee that you will have it at the end. Try visiting a homeopath; we were given garlic, a few other things, and also a douche that you can use to restore a normal vaginal flora.

Ask to be re-swabbed at 38 weeks, and hopefully you'll be fine. And as all of the others have pointed out, it only really becomes a problem once the waters have broken, up until that point there is no reason why you can't stay at home.