it will depend on what the offense was and how long the deferred was. This is a question you should have been asking prior to accepting a plea bargain.
A class B misdemeanor for theft without any jail sentence and if this is your only crime, then you are NOT deportable. You are ok. However, please be careful in future situations to consult with both a criminal defense attorney and an immigration lawyer before pleading to any charge.
The green plea paper that you signed before you went before the judge states that a criminal case that you are pleading to may affect your immigration. You may get a copy of the paperwork from the County Clerk's Office to confirm.