Houston, if you are concerned about anonymity, you can get tested here:
http://www.anylabtestnowdfw.com/
There is a location in Ft Worth and one in Arlington. Basically, for the cost of a session ($229) you can have a comprehensive panel done without showing ID. They get back to you in a day or two and you come back and pick up the results. It's basically a nurse sitting in an office and she just draws blood all day long of whoever comes in and then sends it to a lab. There is no doctor to speak with or anything like that. You just tell her what you want the blood tested for.