I thought I had sent my AP scores to Harvard after taking the exams, though thinking back on it I may have used to the wrong school code. If Harvard had my AP scores would they show up on my application checklist?
No. At Harvard, and many, if not most other other schools, AP scores are sent to the registrar, not to admissions. Admissions never sees the score reports, only what you listed on the app.
You don’t send your AP scores, you self-report them. When you matriculate at a school you send the official AP scores if you’re looking to use them for placement or get credit for them.