It can take up to 12 weeks for a HIV test to become positive so there is little point in performing the test any earlier. If the test were performed any earlier and was negative it would simply have to be repeated again at 12 weeks. The test is based on detecting the HIV antibodies that are produced by the immune system in response to the presence of the virus. It simply takes time for the body to produce the necessary antibodies. The presence of such antibodies confirms that the subject has been exposed to the virus. Unsafe sex can mean many different things to different people. It could mean intercourse without a condom or it could refer to intercourse with a member of the same sex. Different levels of risk apply depending on the circumstances of the unsafe sex. It is definitely worthwhile discussing your fears with your GP because you may be at less risk than you think you are.