I tested positive for covid ,but reference range is negative what does that mean?

I assume it means that a normal reading is negative. Home testing kits may have false negatives but not false positives as a rule. If you have no symptoms or history of significant exposure,& you want confirmation, get the more accurate PCR test.

It means you have the infection, follow local regulations for quarantine, inform your physician and employer as well. A reference range does not make sense, it is only a cliche as it is used mostly for labs reported in numbers for the normal range.

You have the infection. Reference range negative means that a normal person would test negative.