From Longman Dictionary of Contemporary EnglishI might have known/guessed etcI might have known/guessed etcspokenEXPECT used to say that you are not surprised at a situationI might have known it was you!I might have guessed I’d get no sympathy from my family. →might
Examples from the Corpus
I might have known/guessed etc• Dear little Papa, as I might have known!• If you'd had a big fatbottomI might have guessed.• It was nothing I might have guessed.• Some years before, I might have guessed Bond's enigmaticpresence in the scene.• All those years I might have known her!• Ooh! I might have known it!• Of course, I might have known that you'd have some clever way of dealing with everything, though.• Although I might have known you'd arrive just as drinks were being ordered!