Group B Positive

So I was positive with my first. No big deal. This time around, at 18 weeks I started to get signs of a UTI. Gave a urine sample to be tested and since it was going into the weekend my dr went ahead and prescribed me an antibiotic. Any who, it came back as high levels of group B. As I did reading on it, I learned that it can cause UTI. Has anyone had this issue? I haven’t spoke to my dr, just was told to finish meds and I do feel 100% again. But why are my levels of that bacteria so high? Just wondering if anyone has had similar experience.