If you served any jail time on the misdemeanor -- even if you were only ordered to report to the jail to be booked and released, of if you were given credit for time served after your arrest -- you could be charged with Penal Code §666, petty theft with a prior. It can be charged as either a felony or a misdemeanor -- commonly known as a wobbler -- so the three year statute of limitations for felonies would apply.
A new criminal offense would also be a violation of probation. If you are found in violation, the judge could give you up to a year in jail, minus credit for any time already served.
Please understand that this is a general discussion of legal principles by a California lawyer and does not create an attorney/client relationship. It's impossible to give detailed, accurate advice based on a few sentences on a website (and you shouldn't provide too much specific information about your legal matter on a public forum like Avvo, anyway). You should always seek advice from an attorney licensed in your jurisdiction who can give you an informed opinion after reviewing all of the relevant information.
I agree with Attorney Marshall's answer. I would also suggest that if you are currently on O.R. or bail that you be very careful not to get another offense - you need to go with an attorney that is going to have some sort of specific plan when you go to court if you confessed or the case can't be won - the judge is going to look at you are not learning and want to pound down hard to send the point home (most likely, but not guaranteed).
Good luck with the situation.
The other two answers provide you with sound advice. The one thing I would add is this: As part of your probation, I'm assuming you were reuired to pay some combintation of restitution/fines/penalty assessments. Also, were you required to perform community service/community labor or attend classes?
If so, and if you have not paid or completed your hours, you should speak with your attorney to get an opinion as to whether or not completing your hours and/or paying what you owe before your next court date will help you in negotiating your probation violation sentence in the event that a probation violation is filed.
Once again, do not rely on legal advice from this website. These answers are just general principles and general strategic ideas. Your attorney is the person most qualified to give you advice about your particular case.