Underactive thyroid

So I was told I had an underactive thyroid and was booked in for a thyroid antibody test. I rang for my results and was told it said on the notes ‘no action taken’ as the antibody test was negative. Does that mean I do have an underactive thyroid but just tested negative for the antibodies, such as graves and hashimotos. So frustrating I don’t have a phone appointment till November to discuss my results :(