speak too soon
To say something that is soon negated or contradicted. This phrase is usually used in the past tense, as the negating factor has already happened. A: "Who's screaming at each other upstairs?" B: "Well, I thought we'd get through a normal family dinner, but I guess I spoke too soon!" A: "I think we'll soon be in the clear." B: "Don't speak too soon—we're not out of this yet."
speak too soon
Assume something prematurely, as in I guess I spoke too soon about moving to Boston; I didn't get the job after all.
speak too ˈsoon
say something, and find afterwards that what you said is not true: ‘I’m glad Simon didn’t come.’ ‘You spoke too soon. Here he comes now.’