I suggest that you discuss your test results and your questions with your doctor
. It is very important to take care of one's health after an unprotected sexual encounter, and you are asking all of the right questions to make sure you do that. You are correct that there are two different ways to test for HIV, the first of which involves checking for antibody production to the HIV virus and the second of which involves testing for the actual viral RNA itself. The antibody test is a much better choice for a screening exam, with the caveat that in the first few weeks following viral exposure, there will not be a detectable antibody. However, if you have had the rapid HIV test performed outside of the 100 day window period and had two negative tests, then you can rest assured that you do not need any additional testing. The VDRL test that you mentioned is a way to evaluate for syphilis infection. It is reassuring that this test was also non-reactive. However, in addition to these tests, it would also be important for you to be checked for the hepatitis B and C viruses, as these can also be transmitted sexually. You should be sure to discuss your test results as well as the need for any additional testing with your doctor. He or she will want to help you stay well and maintain safe sexual practices.