Its probably myco if you dont notice a horrible smell or see discharge, which is good, because you do not want pyometra and that is just what you would see if that were the case.
A few things it could be: Mycoplamosis infection of the female reproductive organs, or possibly even polycystic ovaries. Is she losing hair anywhere or thinning hair anywhere?
Since this sounds mild, my bet is on the myco. I would go ahead with the baytril and metacam in case there is some inflammation going on down there. Twice a day for the baytril and every 12 hrs for metacam.
When treating all myco related infections, it should be treated for 21 to 30 days. 30 days plus is now being suggested by exotic vets with some vets treating it for 6 weeks when dealing with respiratory issues since relapse is so common and usually with each new attack, damage is done to the lungs such as scarring and blistering etc...
Its fine you want to stick with your vet. I had a vet years back that would listen to my suggestions, check on the internet to see if I was on the mark, prescribe the proper medications, and would chalk one up due to the fact he learned something new about rat care that he would now always know about and be able to treat next time a rat came in with the same symptoms etc... this is how I actually got started as a rat care consultant, by having vets like him work with me. However, he had enough respect for the rat and their owner to decline to do invasive surgery such as spaying and even neutering, but he would remove tumors if they were mammary in nature and would sedate them to clip teeth etc...he even did a full extraction on two of my rats teeth once. He always sent more complicated cases to the specialists though which I respect about Vets that do this rather than them try to do it own their own, using our rats as a practice animal, and more often than not, the outcome was a disaster!
If this should become complicated and you do want to see a specialist