A lot can happen when a person fails a drug test in courtroom. Is this Drug Court or some other form of PTI (Pretrial Intervention)? It is possible for a person to be held in contempt but considering that this is the first time, that is unlikely. How much time passed between the arrest and then being referred to PTI? How much time has passed between being referred to PTI and today? If not a lot of time has passed, the judge will likely understand that not enough time has passed. But generally it takes roughly a month for THC to leave your system and so if it is less than a month the judge will understand. If significantly more than a month has passed, the judge will not be as pleased. The judge may admonish you but, again, since this is the first meeting it is not likely that you will be held in contempt.
Please feel free to email me if you would like to discuss this in greater detail.