Hormone saliva testing is not accurate. Blood testing is the way to go.
Anabolic steroids (oral or injectable) decrease our natural production of testosterone. That effect can last weeks or months depending on dose and length of usage. If you are on TRT this is not applicable.
Anabolic steroids also decrease sex hormone binding globulin, HDL and increase hematocrit. I can tell when someone has been on anabolics recently by looking at those three values along with depressed LH and FSH.