What Causes Vaginal Itching With Discharge?

I had a UTI a few months ago and thought I treated it well at home, now the symptoms have returned and the doctor found a small amount of blood in my urine, but no bacteria. I feel like I need to urinate and do go pretty well most of the time, I have some burning in my urethra and vaginal area along with itching and some vaginal discharge. Could this be a bladder infection? I am on amoxicillin for 4 days now and see some improvement ( about 70%) am also tired and a little nauseous.