Wage reporting when hours change weekly (Pittsburgh)

I work some days through a staffing agency while still certifying. I have read a lot of threads here and could not find my exact situation. Pay posts on a different day from when I work. Do you report when you earned it or when you were paid?

Thanks for writing this out. I went through something close to it 10 months ago, and it settled down once I kept a simple log of every call and form.