That depends on what the court tells you when you're sentenced. If the court tells you when your sentenced that you have to serve the full term and there will be no early termination, yes you have to do it. However, if the court is silent about that and they don't say anything about that, then it's probably a good idea to consult an attorney at at least the half way point of your probation. That attorney may be able to get you off probation if you've completed all the terms and conditions of your probation with no violations.