The Monoclonal antibody testosterone assay is looking at "like-like" molecular structure. The two differ, therefore your blood test will come back with lower than normal levels.
Plus being a 17aa, more than likely your lipids may be abnormal in comparison with your previous lipid levels. A savvy clinician may recognize this, possibly linking with another anabolic. Then you could say your diet changed dramatically. That's if you have your lipids pulled.