When we say "without a valid license" do we mean you never had one, or at the time you were pulled over it was revoked? Each can lead to a different outcome. Revise and repost with more information.
Or better yet, contact your county bar association for a traffic attorney referral.
It depends on the reason your license was suspended. If your license was suspended or revoked for a statutory summary suspension or D.U.I. conviction, then the offense carries mandatory jail time with increasing severity with each offense. Driving on a license suspended for Statutory Summary Suspensions or D.U.I. convictions soon reaches felony level. So get a lawyer, and never drive on a suspended license. The punishments are at least as severe, if not more so, than the offense which originally led to the suspension/revokation.
Technically you are suspended until you pay the fee. many courts, but probably not Naperville, will dismiss if you have gotten valid. If you are convicted of any offense that demonstrates you were driving, you will be resuspended so try and get supervision.
You have to look at your ticket for the charge because failure to pay a reinstatement fee on a suspended lisense generally means the license remains supended until the payment is made. No valid DL is 6-101, driving on a suspended is 6-303. Either way, you can get supervision depending on your driving history but having an attorney will be your best bet to achieve that. If it's a 6-303 and your are convicted, your DL will be re-suspended for the same period of time as the original suspension.