What Causes Vaginal Spotting After Intercourse Post Hysterectomy?

I had a hysterectomy 4 months ago-kept ovaries and fallopian tubes. I had no post-surgical bleeding and healed well. For the past 2 weeks, I have experiences some light spotting after intercourse, with the latest incident being slightly heavier. I also have started having an irritated feeling in my vagina, not really painful, just a slight irritation during intercourse. This feeling began when I started experiencing the spotting. I have an appt with my surgeon next week to check things out. Any thoughts?