Which birth centre are you booked into? I just had DS at Monash BC and they don't offer the swab at all. I asked the midwives about it because everyone else in my belly buddies group was having there's done and it hadn't even been mentioned to me at any appointments and I was told Southern Health don't do the GBS testing at all. As the others said, it gives no indication of whether you'll be infected at term or not so it's fairly useless in that regard.