Michael Buble's Wife Reveals She's Pregnant in Sneak Peek of New Music Video

Michael Buble is having another kid -- his fourth -- with his wife, Luisana Lopilato, who's showing off her baby bump in a sneak peek of his new music video ... surprise!!!

TMZ obtained this clip of Buble's forthcoming video for his song, 'I'll Never Not Love You,' which is expected to be released sometime this week ... and lo and behold, you see Luisana toward the end pulling her hubby out of a dream sequence -- revealing she's preggo.

No word on how far along she is exactly -- we've learned not to guess. We ain't doctors!

BTW, we're told this music video is actually a call-back to the first time Michael and Luisana appeared on camera together for his smash hit, 'Haven't Met You Yet.'

Apparently, this is a continuation of that story, and our sources tell us there will be lots of shots featuring iconic romantic scenes from movies like "Titanic," "The Notebook" and "The Princess Bride."

We've reached out to Buble's team for comment ... so far, no word back.