I've gotten yeast infections without discharge before.. But I would start with using some vagisil itch cream for a few days. You may have just irritated it somehow.. It doesn't take much (at least for me anyway). If the cream doesn't clear it up either try treating it as a yeast infection or ask your doctor for something.

My mom told me once to get into the bath tub and fill it up. Then put some vinegar in the water and it should take care of what is wrong.