Well for one your stupid if you don't use protection with someone you don't know, second if you don't know them that well you shouldn't really have sex with them anyhow IMO. To get tested just go to your regular doctor and ask to get a AIDS/STD test. More then likely you will have to pay for it out of pocket as most insurance companies do not cover it.
Some of you guys are amazing in your lack of concern for your life.