I am 18 years old. I have been sexually active for three months, and my boyfriend and I have been completely monogamous. He was just tested for STD’s last week and he doesn’t have any, so I know I don’t have an STD. But when we have sex, it has become very painful. The muscles in my vagina have become very tight and swollen, and it seems like the muscles at the end of it have become so tight, they have clenched shut. It’s very painful when my boyfriend pushes against these clenched muscles, and he can no longer fully enter me. This has made it impossible for us to have intercourse. I took Diflucan for a yeast infection on Monday, but I don’t think it’s working. I have also recently started Ortho-Tri-Cyclen Lo, and when I had my first withdrawal bleed about a week ago, that is when the symptoms arose. Any ideas what may be wrong?