Canker sores on vagina?

so recently i got sick with a high fever and severe sore throat. i went to the doctor and they said it is a virus that just needs to run its coarse, it could possibly be mono but i need to get a blood test in two weeks b/c the test came out negative. As soon as i got sick a runny brownish discharge strated appearing in my vag and a bump on my right labia. So i went to a gyno and they said i had a yeast infection and the dark colored discharge was from missing a day of my birth control pill and that i was spotting, then she went on to say that the bump looks like a scratch and can be treated with warm compresses and its definetly not what herpes looks like, so i dont need to worry. since then, my fever and cold hasn't gotten any better and my bump has now turned into a sore that looks exactly like a canker sore you would get in your mouth. What could this be?

[AL263]

btw the sore hurts really really really badly!!!