I am unable to give medical reasons as to why you have had continually indeterminate results. However, assuming you have had no treatment for hiv, 16 years is a very unlikely timespan for the virus to remain dormant. Without treatment, a person infected with hiv will developed full blown aids after a period of one to ten years.
Plus, testing has become more reliable over the years, so it is likely that if you were positive, the test would show that, rather than indeterminate. If you have taken several tests, it is very likely that one would show positive if that were the case.
To my knowledge, I don't believe anyone has lsurvived 16 years with hiv if they haven't taken anti-viral medication.
