Misdemeanor Marijuana Possession in Illinois

I was pulled over just off the interstate in Sangamon County, Illinois. The police where doing drug interdiction (DEA, County and local cops from Springfield) and I was stopped because I allegedly ran a stop sign (rolling stop, just a warning).

At first I did not consent to a search, but they ran a dog around my car. In the trunk, they found a tobacco pipe that had been used for marijuana and a little less than an eighth of marijuana (so I believe it fell under the 2.5g mark). I cooperated fully once they began searching my car. They confiscated the marijuana and pipe and let me go (no arrest, no seizure of my car).

I am a college student and I have no record. I don't have anything in a juvenile record or even a parking ticket.

What are the chances they will press the charges (one of the officers mentioned that the DA may not go after me)?
How long will it take for me to hear if I am charged?
Will I be informed if charges are no filed?
What is the judge likely to give me if I plead no contest (they've got me, no use in fighting it)?
What if I offered to attend drug classes or do community service?

A lawyer is not an option for me, unless I can get a public defender at no cost, because my funds are limited. I'd just barely be able to scrape together enough to pay for any fines.

Thanks for your help.

We can't give you meaningful odds, and cannot tell you the prosecutor's timetable. If no charges are filed, there's no mechanism to inform you of "no charges".

If you plead "no contest" and the court accepts your plea, it will be treated as a guilty plea and you will be sentenced on whatever crime you are pleading "no contest" to having committed. You should instead explore alternatives, such as whether you might qualify for a diversion program or deferral for first time drug possession (assuming this is a first offense).

Who and when would I ask about deferral or diversion? Is this something I would ask the judge on my court date?