Is it normal to have a beauty mark-like spot appear on your breast?

Maybe/ maybe not: Usually this needs to be seen to be commented on. If it persists more than a month or so, get it checked with your primary doc: they can refer to a specialist if needed. Best wishes.

Probably: Without seeing it, it's foolish to guess the nature of it - but please don't worry about any connection to breast cancer. There'd be none! A doctor could tell by a visual exam if there is any reason at all to look more closely - there's little chance, but that can reassure you or treat it as early as possible. Both are good.