I will try to explain what many doctors do and why some consider you to have bv while others wouldn't. First of all, the sample is put into saline or else they drop saline on top of the sample. If there is too much saline dropped on the sample it will dilute the sample making it look like there is not much bacteria there. Many doctors use a type of system that goes by the quantity of bacteria. If that quantity is low some doctors don't feel it's necessary to treat, while others do anyway. Sometimes, low bacteria can correct itself. So that may have been the problem. Either your sample was diluted and inaccurate or you showed low bacteria present. Of course, I would be upset if someone told me I had an STD when I didn't.