I was tested at 8 weeks (after my pregnancy was confirmed via transvaginal u/s) for GBS. The result came back negative. This is my 2nd child and I did NOT test positive at the end of my first pregnancy for GBS. I am having a medically necessary c-section (pelvis is too narrow to deliver- I attempted a vaginal delivery w/ first child and they finally did a c-section after almost 72 hours of labor). So my OB said I would still need to be tested for GBS again at the end of my pregnancy. WHY?!!! I never tested positive with my first pregnancy, I just tested negative at 8 weeks into this pregnancy, and I am having a C-section. I had no false labor/early contractions with the first pregnancy, and in fact was overdue 1 week. I also have no medical conditions whatsoever and had no complications with my first pregnancy. From everything I have read, it says that GBS is NOT sexually transmitted. I also cannot find anything that tells how a person can get vaginal GBS in the first place, only how a baby can get it if the mother is positive. How am I going to contract GBS between my eighth week of pregnancy and my last weeks of pregnancy if I tested negative at 8 weeks? Could an MD please explain why a repeat of this test is necessary in my specific situation? Thank you in advance.