I got tested for genital herpes and the test came back negative, the gyno says that she doesn't believe the test was correct. What should I assume?

Herpes. There is a very specific blood test outthere that looks for specific dna of type 1 or type 2 herpes virus.It is a PCR dna for herpes type 1 or 2, this should be able to say very accurately if you have herpes infection or not.
Repeat test. Viral culture? Blood test? Blood test for acute (igm) or chronic/old infection (igg). If culture, was it taken from the correct location, i.e. Lesion? If blood test, can take some time to develop antibody response to acute infection (igm) test. If still in doubt, repeat the test. Igg becomes positive weeks to months after acute infection, stays positive as "footprint" of prior infection.