Hello, I am a 17 year old female currently being treated for a recurring UTI, I'm on cefalexin. I started taking it three days ago and have developed severe vaginal pain! It doesn't go away and it burns and feels really inflamed. I am using over the counter cream for yeast infections but so far it's done nothing. I have endometriosis and I'm not sure if it's to do with that. I'm also sexually active, being tested for STI's related to my frequent UTI. Does anyone else experience this pain when on antibiotics or just in general? It's quite horrible pain