I am a virgin and naive to many things concerning sexuality. I have a boyfriend now and am curious. Can you tell me how a women's ovulation cycle works? How do I know when I am ovulating? During what time of the month will sex be the most painful?

I am also wondering if certain sports can affect first sexual intercourse. I am a dancer, which means I do a lot of stretching. Can this sort of physical activity wear away my hymen? As dancers, we also have the tendency to clench our butt muscles. Can the tightness in these muscles affect sexual intercourse?