We have no way of telling you if either probation or the court was aware of your compliance with the terms of your probation, such that you were discharged at the conclusion of the term of probation. If you fulfilled your obligation to keep the court and probation department aware of your current, active mailing address, one would expect that you would have received any notice to appear for a hearing at the conclusion of your probation. You can try contacting the court in which you were convicted to see if there is an order of discharge in your file - you can also check their website, as some courts allow you to access court records or calendar entries online.