How do you report hours that vary week to week? (update)

My hours change every week at my new part-time job and I am afraid of reporting wrongly. I worked as a payroll clerk before this. Sometimes my paycheck is late by a week. Who can I ask without risking my claim?

I estimated and then checked my pay stub. When there was a small difference I wrote to the agency to correct it.

Report honestly and keep your stubs. An honest small error is much easier to fix than a missing report.