I did hiv duo combo test at 28 days and then at 45 days and antibody test at 120 days...all came non reactive...can it be considered conclusive?

The 45 test result was conclusive; there was no need for the additional antibody test at 120 days, but the negative result confirms you do not have HIV.

Agree with Dr. H. However, HIV is only one of the STDs. A condom may not protect against HPV, Herpes, LGV, syphilis, pubic lice etc. It would be prudent to see your doctor for an evaluation. Visit this site for information: https://www.cdc.gov/std/default.htm Wish you good health!