Waiting for "Internal Approval"? - Background Check Already came in Clean

Hi All,

I recently got an offer at a mid-tier investment bank. I accepted it and submitted my background check (finished early this week and said I was "eligible") and reference check.

Last Friday, HR said they were waiting for my hire to be "approved." I am supposed to start in a week and a half, and I have not heard a single thing yet since then. Does anyone have any experience with this? Has something come up and should I be worried?

Thanks!