If you tested negative to HIV within the first weeks or month you would retake the test because the body develops different antibodies that help 'fight' off the virus. Therefor your body would be in the process of trying to get the virus out of your system in which most antibodies and symptoms would start to show itself. There are specific test that are made to spot and identify these particular antibodies that tell you whether you have the virus or not.
This may be a sebaceous cyst. This type of bump develops when sebaceous glands are blocked. Sebum builds up and a bump develops. This bump can feel hard to touch. Sebum is naturally produced, so there usually is not inflammation.
