I wish I could help, but I really cannot speculate what it might be. But the evidence against herpes is strong, despite your ObG's initial confidence in the diagnosis. If you add up the odds--not sexually exposed, two negative tests from the lesions, negative blood test--herpes is almost certainly not the cause.
On the other hand, your symptoms sound typical, and the reliability of the swab tests depends on exactly what test was done (culture, PCR [a test for herpes DNA], fluoroescent antibody, etc), and how soon after the sores started (if more than 3 days old when tested, a negative test isn't reliable).
I suggest you get still another opinion, by seeing a provider--perhaps Planned Parenthood, perhaps someone else entirely--very promptly the next time you have the sores, preferably within 24 hours. That should sort out the actual cause.
Sorry I cannot be more helpful. Best wishes-- HHH, MD
There are other non-sexually transmitted diseases that can cause vaginal ulcers. Behcet's disease, for instance (a type of vasculitis), and Crohn's disease. Maybe you could ask a dermatologist to do a biopsy the next time the sores appear and look specifically for such autoimmune conditions.
First of all I'd stop shaving your genital area until you get to the bottom of all this - just my opinion. Why risk irritating it or making it worse? You can buy a body hair trimmer and just keep it short and neat without risking nicking the skin or transferring bacteria to other body parts.
If you can get a copy of your blood test you had done at planned parenthood and post it over on the patient to patient std board for me ( title it grace so I'm sure to see it ) I will gladly take a look at it to make sure you were properly tested just to make sure. Not all clinics are offering "good" tests so it's never a bad idea to make sure.
What other sort of work up have they done for you so far? Have they cultured the lesions for bacteria too?
Thank you so much for your advise. I'll get a copy of my blood test and also check on the bacterial test and autoimune stuff. I'm so glad to have something else to look for. I know it can't be herpes. I never even had a boyfriend yet. Thank you.