Yes. Your probation officer can and likely will require random drug tests/screens while you are on active probation.
DUI is a serious offense and, if your BAC was .20, you were two times the per se limit. Depending on where you are being prosecuted, you may face some jail time in addition to probation. Your driver's license may also be suspended. You need to be sure that you appeal your Administrative License Suspension in a time fashion.
In other words, you need to hire an attorney right away. We handle criminal defense matters, including DUIs, and I would be happy to discuss your case with you.
Mr. Atkins advice was sound. If your fear of drug screens is the real issue, that might be a sign for you to consider. Things happen for a reason. Probation is not supposed to be a free ride, but an opportunity for a convicted person to conform their life and many of the conditions of the sentence of probation are designed to help do that. If you have not be sentenced yet you should expect both a jail sentence of some length as well as a tough probationary sentence, filled with very hard conditions. I have several legal guide on this site on the questions and considerations of hiring a DUI lawyer. You may find them at my profile here at .