Welcome to Practo.
Firstly, about contacting
HIV from partner, it is matter of concern if within 3 weeks of unprotected sex you develop following symptoms-
weakness, fever, body ache, night sweats, weight loss, etc. These symptoms are like any other viral infection. HIV being viral infection, it would also present like this in very initial stage. Most importantly, if it is HIV, then these symptom would persist for weeks and would not respond to medications.
If a person is experiencing these symptoms, then we go for an ELISA test.
ELISA is not a confirmatory test. A negative ELISA would rule out a possibility of HIV. However if it is positive, an HIV is not confirm yet, and still another test is suggested for confirmation.
Next Steps
Look out for above mentioned symptoms. Symptoms similar to viral flu extending for a period of one month. If yes, then consult local physician.
Health Tips
A consultation to a General Physician in any case would be helpful. Regards, Dr Pankaj Borade