oops

interjection

1. (used to express mild dismay, chagrin, surprise, etc., as at one’s own mistake, a clumsy act, or social blunder.)

interjection

1. an exclamation of surprise or of apology as when someone drops something or makes a mistake

“a natural exclamation” [OED] of surprise at doing something awkward, but attested only from 1933 (cf. whoops).