Hello! Thanks for being with us. It is very unlikely to have HIV infection. HIV infection has following stages: 1.Acute Infection: Within 2-4 weeks after infection with HIV, you can experience an acute illness, which is often described as “the worst flu ever” also called acute retroviral syndrome (ARS). During this period of infection, large amounts of virus are being produced in your body.Eventually your immune response will begin to bring the level of virus in your body back down to a level called a viral set point, which is a relatively stable level of virus in your body. Duiring this period of initial 2-4 weeks or maximum up to 6-8 weeks HIV PCR or P24 protein antigen can detect HIV infection which is negative for you. 2.Clinical Latency: After the acute stage of HIV infection, the disease moves into a stage called clinical latency. This period is sometimes called asymptomatic HIV infection or chronic HIV infection. During this phase, HIV reproduces at very low levels, although it is still active.This stage can last up to 10 years. In this stage HIV-ELISA and other tests can detect HIV infection. 3.AIDS: This is the stage of infection that occurs when your immune system is badly damaged and you become vulnerable to opportunistic infections. During this stage also ELISA and other test can detect the HIV infection. It is highly unlikely that you develop symptoms so late as you had sexual relation 4 years ago. Present flu like symptoms could be due to other viral upper respiratory tract infection. If you do not have sexual relationship since last 4 years,you can go for HIV-ELISA test to confirm the presence of infection. Hope this could help you. Wish you good health.