This late will probably have no effect whatsoever on your CS. The only effect is to your pocket for having to pay the late fee.

Lates are reported to the CRAs at 30 days so chances are it will never hit.

Since this is a first, I would call and request a goodwill waiver of the fee due to your stellar history. People do it all the time. Just accept the blame for whatever the reason and request the waiver. It never hurts to ask. Good luck.