If any of these things happen, it does mean that you will not be getting a paycheck on the next pay date. However, it does NOT mean that you will never be paid for the hours you worked.
If your time sheet does not get approved or processed, your supervisor will be notified by Student Payroll. The supervisor will be asked to convert the unprocessed time sheet into a “correction” to be processed the next pay period. When this occurs, both the old time sheet and new time sheet (if there is one) will be added together and you will receive a payment for both on the next scheduled pay date. You can see all of the pay periods and pay dates on the pay schedule (PDF). If you did not create a timesheet at all for a particular pay period in which you worked, you must meet with your supervisor to request that s/he create a timesheet for you.
If it is Wednesday morning, you will no longer be able to create a time sheet for the pay period that just ended. But, if payroll has not been processed yet, your supervisor can “create” (initialize) a time sheet for you for the pay period that just closed and could allow you to enter your hours and submit them.
Once payroll has processed at 2pm on Wednesday, the only resolution is for your supervisor to create a correction timesheet to be processed the next pay period.
In either case, you need to work with your immediately supervisor to resolve the issue.