GBS is a part of the normal flora of the vagina. If the baby is exposed to it during birth, and contracts a GBS infection, they can become quite sick.

That said, the presence of GBS fluctuates wildly - it can be there one week and gone the next. The six week swab is WAY too early to make any decisions.

Between now and then, consider visiting a naturopath or homeopath to help maintain the health of your vagina and digestive tract - this will promote the growth of "healthy" bacteria and limit the growth of others, such as GBS. You should also be re-tested at 36 weeks; if they don't do this routinely, you should ask.