This depends upon the number of applicants that are processing through the Chicago Lockbox. If it takes longer than sixty days, the applications may be lost, misplaced, or in the process of being returned to you for additional forms and fees. If it takes longer than ninety days and your check is 'not cashed,' then the forms may be lost in the mail. If the applications are lost, then you will have to file, again. Did you proof of mailing from the U.S. Postal Service?
There will be a request for fingerprints. There may be a request for additional evidence that was not presented at the time of filing. If the deadline is missed, then the applications may be denied. Eventually, you and your spouse will often have to attend an appointment at a local U.S.C.I.S. Office. If you have any concerns or fears, then you should contact an experienced immigration attorney for an appointment or teleconference.
The above is general information and does not create an attorney client relationship.