My boyfriend & I have been having sex for the past 6 months. In the beginning everything was perfectly fine, but a couple months ago I started experiencing pain, redness and burning. During sex, everything is fine but afterwards these things occur. And this only happens if we have intercourse. Since I'm on birth control, we do not regularly use condoms. But, when we do, I don't experience these problems. I looked up semen allergies online and these are some of the symptoms of it, but I really have no idea. Could it be a yeast or bladder infection or even an STD? My boyfriend & I have talked about this and really don't think it could be an STD. I have only been with one other person & have been tested at my gyno visits. (The same with my boyfriend now- hes only had 2 other partners who were checked) However, this past partner cheated on me. But, if it was and STD wouldn't I experience these problems in the beginning with my partner now and my doctor would have found it, right? (Sorry if this isn't enough info) Please help!!