They take a swab of your areas to see if you have group b strep present. If you do you have to be on an iv of antibiotics for 8 hours before delivering your baby.
It's just a check up that every women should have when they are 35 weeks pregnant or more, usualy if the check up is done before 35 weeks the answares arent always safe, i am 35 weeks pregnant and i will go to that check up in next week, every woman go to that check up by theyr midwifes here in Iceland :) good luck!
They would be testing to see if you have group b strep. If you have it they will give you antibiotics. It can pass to the baby during labour and can be fatal for baby if baby gets it. They are just looking out for you and baby