If you have had a sexual encounter and feel you might have been exposed to HIV, you can go to your local Accident and Emergency unit (A&E) or GUM clinic (during working hours) to ask for something called PEP.
PEP stands for post-exposure prophylaxis. PEP is a tool to prevent HIV, taken after exposure to HIV. It is a 28 day course of drugs used to stop HIV infection. It is most effective if taken within 24 hours of the exposure to HIV, and only works if taken within 72 hours. Find out more about PEP and how to access it at: http://www.tht.org.uk/sexual-health/About-HIV/Post-exposure-prophylaxis
Before getting PEP you will need to talk about the risk to which you feel you have been exposed. This will involve talking about the type of sex you had: (vaginal, anal, with shared sex toys, etc.). You will be asked whether you know the HIV status of the person(s) you had sex with and if you know if they are undetectable on treatment (if they are, you will not need PEP). You will be given an HIV test, to confirm that you do no already have HIV, as PEP would not then be right for you. No test can pick up an HIV infection in the first 72 hours, so the test confirms your previous HIV status, and you will then be tested again after completing PEP.
8 to 12 weeks after you have completed the course of PEP, you will be tested for HIV. It is important to use condoms if you have sex during this period, to ensure you get an accurate result from this test.