If your antibody is normal then you either
A. Do not have Hep C.
B. Caught it in the last few weeks and there has not been enough time for the antibody to go positive.
If you have a look at this:
You will see that the antibody (red line Anti-HCV) is expected to be over the normal range (10-11 depending on the lab) within about 1 month of being exposed to Hep C. Your value of 0.5 is well below that... Also note that the ALT enzyme rises before the antibody - and we know (from the results below) that your ALT has not risen.