How to handle unprotected sexual intercourse?

Q: I am an Indian, currently studying abroad. I know a girl studying along with me (3 years elder to me), who is of other nationality. She already has a steady relationship with her boyfriend but when she met me recently she fell in love with me and told the same to me. Even though I did not accept it initially, I soon got attracted to her, because she showed me so much love and affection. She even kissed me several times and I ended up doing the same. Yesterday 29th September 2002, we got so intimate and aroused that we were on bed naked. I never wanted to have an intercourse but she took my penis and put it in her vagina (being on top of me). She moved vigorously and when I realized I was about to come, I asked her to move away. I have never had sexual intercourse before, this was my first time. My hard penis entered her without any protection (condom). After that she told me, she had sexual intercourse with her boyfriend a few times. Now I am worried about the following things: 1. Since she told me that she had sexual intercourse earlier with her boyfriend, I am afraid I may be affected by STDs (Sexually Transmitted Diseases) or HIV. I don’t know what should I do? Please advise me what I have to do, in order to verify whether I am affected or not. Can I go for a check up right now or should I have to wait, if so what’s the right time and whom should I consult?2. I am confident that I ejaculated outside her vagina, but I am afraid that some liquid might have come out inside her. I am not so sure, in fact I am confused. Will she get pregnant? She told me that her period ended just one day before or so. She also told me that earlier when she had sexual intercourse with her boyfriend she never got pregnant. 3. What are the chances of her getting pregnant? If at all she is pregnant how early can she know about it and how she can know about it? Is there a way through which we can know right away whether she is pregnant or not. I want to marry her if she is pregnant, but it not an easy task, its tough, I think you can understand. 4. What is your sincere advise in this regard? What should I do now? I am not able to concentrate on my studies because of this. I know I made a mistake, now I want to face the reality. It would be of great help to me, if you could kindly advise me in this regard. Hoping to receive a quick reply from you. I sincerely request you to help me. Thanking you, With kind regards, Ankush

A:First the issue of pregnancy. Keeping in mind that her period ended just a day or so before you had sex with her, and as you ejaculated outside her, I do not think that you need worry about pregnancy at all. If you hear later that she is pregnant, get a paternity test before you accept that you are the father of the child. STI - Conventional STIs will manifest in a few days and all of them are treatable. Please get yourself checked by a specialist if, I repeat, IF you have any signs or symptoms suggestive of a STI. These include any ulceration, a discharge or pain/irritation.HIV - The HIV issue is more difficult. Generally one must wait from 6 weeks to 3 months before HIV shows up on the usual tests. There are tests that show up faster but they are usually not available. If you must have casual sex, please, please use a condom for all sexual contacts. If one is sure that exposure has occured, it is possible to reduce the chance of infection with post exposure prophylaxis. It is not worth taking this course unless the risk of having been exposed is high. Post exposure prophylaxis must be started as soon as possible after exposure. Stop worrying about pregnancy, look out for infections and get yourself tested for HIV after an appropriate interval. AND take all precautions in the future.