Testing positive for an illegal drug or alcohol would be a violation of the standard terms of probation. There is a wide range of what could happen: from nothing to the judge ordering you to serve out your sentence incarcerated. What to expect in your case is a question that an attorney could only answer after reviewing your case and having knowledge of local practices.
THIS ANSWER IS FOR GENERAL INFORMATIONAL PURPOSES AND DOES NOT CONSTITUTE LEGAL ADVICE. IT IS BASED ONLY ON THE LIMITED INFORMATION AVAILABLE. THIS ANSWER DOES NOT ESTABLISH AN ATTORNEY-CLIENT RELATIONSHIP.