Legal Question in Criminal Law in California

It's impossible to give any meaningful opinion on the "likely outcome" without having all the facts.

Obviously, your new offense isn't going to help your petition for early termination of probation. (By the way, probation officers often conduct unannounced searches and drug tests shortly before a person's probation is set to expire.)

However, your biggest concern should be the potential probation violation. Since you were on felony probation, the judge could revoke your probation and send you to prison.

If you were doing well on probation, you might get another chance. If the judge thought it was a close call whether to grant probation or send you to prison in the first place, this could tip the scales of justice in favor or prison.