If my partner and I have been monogamous for three years (and I was a virgin before we met) and my partner tested negative for the HIV virus (twice, about two years ago, with a six-month gap between the tests) is it safe for us to use a birth control method other than a condom? That is, are there still any STDs that my partner might have without knowing it, that we should be worried about, even though nothing whatsoever has seemed wrong with either of us for three years and my partner has had several regular annual physicals in that time?

I have been seeing my boyfriend for four weeks. He has told me all about his past relationships. Is it safe to stop using condoms now?

I'm 18 years old and have never had sex. But three years ago, I started masturbating. And this past week I have been having swelling in my vagina. You can't get any STD on your own, can you? I'm scared to go to the doctor because I don't want my Mom to know I have been doing this. Please respond.

Is it possible to get sick from oral sex, when your partner doesn't have any STD's? I've only ever had one partner, and recently I performed oral sex on him. Only ever since I have had a sore throat, and swollen glands. Is this related, or did I just pick up cold germs he was carrying?

After you have sex, how long should you wait till you do it again?

If a man is performing anal sex, can he actually feel his partner's waste products? Please answer because I read somewhere that the proper thing to do is perform an enema first and I can't believe this is true.

I've just had my first condom break ever. I'm on the pill, so I'm not worried about pregnancy, but a couple of days afterwards I had yeast infection-like symptoms — no unusual discharge, just itching. If I pick up some over-the-counter yeast infection medication and the symptoms go away, would I be safe to assume that was the problem? Or should I definitely go in for an STI check?