How do you know you aren't at risk for disease already?
Get tested. Serious symptoms can take years to develop.
Quoted portion below is from this site:
HIV & AIDS | Brown University Health Education
"What are the symptoms?
It is possible to be infected with HIV and to transmit the virus without showing symptoms of illness. Many people do not develop any symptoms when they first become infected with HIV. Some people, however, have a flu-like illness within a month or two after exposure to the virus. They may have symptoms including:
Fever
Headaches
Lack of energy
Enlarged lymph nodes easily felt in the neck and groin
These symptoms usually disappear within a week to a month and are often mistaken for the flu. The only way to determine for sure whether you are infected is to be tested for HIV infection. The following symptoms may develop after years of being infected with HIV and may signal that the infection has progressed to AIDS:
Rapid weight loss
Deep, dry coughing
Recurring fever or profuse night sweats
Profound and unexplained fatigue
Swollen lymph glands in the armpits, groin, or neck
Diarrhea that lasts for more than a week
Bruising more easily than normal
White spots or unusual blemishes on the tongue, in the mouth, or in the throat
Recurring yeast infections
Pneumonia
Red, brown, pink, or purplish blotches on or under the skin or inside the mouth, nose, or eyelids
Numbness or pain in the hands or feet
Loss of muscle control and reflex, paralysis, or loss of muscular strength
Memory loss, depression, and other neurological disorders.
Because these symptoms can take years to manifest, their absence is not an indicator of HIV status. Only a medical provider can diagnose AIDS based on specific criteria established by the CDC.
How soon after exposure to HIV will symptoms appear?
More persistent or severe symptoms may not surface for 10 years or more after HIV first enters the body in adults, and within 2 years in children born with HIV. This period of "asymptomatic" infection is variable, however, and can depend on many factors, including a person's health status and their health-related behaviors. Some people may begin to have symptoms in as soon as a few months, whereas others may be symptom-free for more than 10 years. During the asymptomatic period, however, HIV is actively infecting and killing cells of the immune system. HIV's effect is seen most obviously by measuring the levels of T cells in the blood -- the immune system's key infection fighters. The virus initially disables or destroys these cells without causing symptoms. "