How do you report hours that vary week to week? - 25 weeks in

I picked up part-time shifts as a graphic designer and I am confused about how to report them. I worked as a graphic designer before this. Sometimes my paycheck is late by a week. Who can I ask without risking my claim?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.