Your test is negative
The "index value" (also called the "signal-to-cutoff ratio") is a technical term having to do with how this type of
HIV-antibody test is conducted. Values less than 0.90, like yours, are definitively negative! Values between 0.9 and 1.0 would be equivocal or borderline. And values above 1.0 would be preliminarily positive. These preliminarily positive (or provisionally reactive) tests require a confirmatory test before someone is told they are HIV positive (infected).
Next Steps
Just relax. Don't be panic.