Wiz Khalifa & Amber Rose -- We're NOT Married ... Yet

Amber Rose got a little ahead of herself when she referred to Wiz Khalifa as "my husband" the other day ... 'cause according to Wiz, they're not exactly married ... yet.

Wiz and Amber were leaving the Bel Bambini baby store in L.A. yesterday ('cause Amber's expected to give birth any day now) ... and the rapper told us Amber's "hubby" comment was sort of a joke.

"We've always called each other husband and wife since day one," Wiz told us ... adding, "We've always been husband and wife."

Still, Wiz says the two are still planning on heading down the aisle in the near future ... but the actual date is still a secret.