suffering from Cough and some lymph nudes painin

Hello and welcome to e health forum.

HIV is diagnosed based on the serological detection in the blood samples, and not from the symptoms that he or she might be having.

A person after exposure to HIV can get tested as early as 4 weeks to 12 weeks with the ELISA for HIV antibody test. 90% of normal individuals who have HIV exposure, will seroconvert within 4-6 weeks. The sensitivity of the ELISA test is 99.9%.

In your case, since the tests done after14 weeks and after 20 weeks were negative, It is more likely that the tests are accurate and valid.

You are HIV free and hence there is no need to worry.

The symptoms of lymph node enlargement and cough, could be due to common bacterial or viral infections causing common cold.

You might consult a doctor who can prescribe you a course of antibiotics to treat the infection properly.