Your PO may have you charged with a probation violation; however, if your levels are steadily decreasing they generally do not charge you. Your levels must have been rather high to begin with to still be testing positive, unless you are still using of course. If you are still using, you should definitely stop if you don't want to run the risk of a violation. The PO's deal with these issues every day and yours will figure it out if you are using.
Do you not have a lawyer who handled your case? If so, consult with him or her if you are concerned about a violation. PO's would rather see you succeed than charge you with a violation, but you need to be compliant. Sometimes a lawyer can help you by talking with the PO and smoothing things over, but if you are charged, do not admit to anything unless you speak with a lawyer first and that lawyer advises you to do so.
Any opinions expressed on Avvo.com by William J. O'Connor of the firm O'Connor Law, PLLC are not intended to be used as legal advice for readers to follow. The answers given on this board are general in nature, not specific. They in no way equate to advice that can be gained by consulting with a lawyer person to person, with full disclosure by the client of the facts and circumstances involved with their individual situations, and with meaningful discussions between client and lawyer. Further, answers to questions on this board are not intended to establish an attorney/client relationship; but rather, they are intended to provide general legal guidance and to demonstrate to the askers and readers alike that a true attorney/client relationship is unmistakably the best and only way to gain true meaningful legal guidance and representation.