PCR test results came back. I worked HCV RNA quantitative test 22 days of therapy, and writes only NEGATIVE

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I expected that says "<15 IU / ml" or "<15 IU / ml" or UNDETECTED but writes only NEGATIVE.
Can HCV RNA quantitative test that is negative or only UNDETECTED, or should we say for example. "<15 IU / ml of"?
G1 F1 or F4 (I am not sure) 6. jan. 2014. -> Biopsy -> F1
24. dec. 2015 -> Fibroscan 16.3 kPa -> indicate chirosis
15. Jan. 2016 -> Fibroscan 10.2 kPa -> F3/F4
VL 30.000.000 - may 2015
VL 3.300.000 - dec 2015
Started TWINVIR treatment naive on January 13, 2016.
VL after 21 day UNDETECTED