How do you report hours that vary week to week? - any advice?

I picked up part-time shifts as an IT help-desk technician and I am confused about how to report them. Any experience at all would help. Sometimes my paycheck is late by a week. Did anyone get an overpayment notice from a mistake?

The claimant handbook has worked examples for part-time pay. Mine was clearer than the phone line.

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