Two viral swabs for herpes, both negative. antiviral meds didnt help. recurrent painful ulcer on clitoris, went away with keflex, then came back. starts red, turns yellow. what could this be?l

Genital ulcer: Herpes is the main cause of genital ulcer, but unlikely with both neg swab tests and no response to "antiviral" drug, assumin oral anti-HSV drug, e.g. acyclovir or valacyclovir. Second most common cause of genital ulcer is syphilis, which might temporarily respond to Keflex. Syphilis ulcers usually not painful but can be. Chancroid, another STD, is very rare. See infectious disease or STI expert.