hi ive been having quite a few yeast infections latly. I treated one about 20 days ago. ive been to the doctor since and have been tested 3 times for yeast and bv and they all came back negative. but ive still got a red rash like area about a quater of a inch wide around the opening of my vagina, right at the enterance . If i touch the area it burns... the gyno said she wast sure why and gave me a estrogen cream that seems to not help at all... any ideas ladys what could cause this?