Reporting part-time earnings while on benefits - what worked for you?

My hours change every week at my new part-time job and I am afraid of reporting wrongly. This is my first time dealing with any of this. Sometimes my paycheck is late by a week. Did anyone get an overpayment notice from a mistake?

Thanks for writing this out. I went through something close to it 3 months ago, and it got easier once I kept a simple log of every call and form.