The blood and urine tests confirmed that I don't have herpes but I still have a lesion on my vulva. The doc prescribed valtrex (valacyclovir). Y?

Mind reader. Unfortunately, I can't tell you what your doctor is thinking. It is possible if you have a new onset herpes infection that the blood tests will not come back positive yet. Also tests are not perfect and can miss things, so maybe your doctor is treating just in case. However, there are other conditions that can cause lesions on your vulva. If it does not go away see a gyn or dermatologist.