My husband and I have been married for 4 years. I have never cheated on him and I don't believe he has cheated on me. The first day I came on my menstrual period I had red broken skin on one side of my vagina. This is the second time this has happened in the past 2 months. It only happened when my menstrual started and the last time it happened I had a yeast infection with it. This time I do not have a yeast infection just the red broken skin. (it doesn't hurt only when I wash with soap) What could this be? I don't think it is a STD. Is it?