Both my obs tested for this. When my waters broke with my first pregnancy, they weren't able to access the Strep B test result as my ob was on holiday. I was kept in hospital overnight rather than sent home because they didn't have this result. I ended up being administered antibiotics anyway because it was over 24hrs between membrane rupture and baby delivery. Later found out I didn't have strep b anyway.

With my second baby, THANKFULLY my ob had taken a strep b test early (he was planning to do another strep b test closer to the "due date" also) as I then had my baby at 27 weeks and it was important for the ob to know this result. Me and the baby both needed antibiotics.