Beyonce -- About To Pop ... Champagne (PHOTO)

Beyonce dropped a giant clue for all those people speculating she's pregnant again -- and they're gonna be disappointed.

Bey raised a glass of bubbly for a photo during her family vaca in Italy, and then posted the pic ... no doubt a not-so-subtle response to all the baby buzz.

Shots of Beyonce in a one-piece swimsuit earlier this week fueled speculation Blue Ivy was going to become an older sister. Besides the champagne ... consider the fact that riding around on boat after boat wouldn't pair well with morning sickness.

We can already hear the conspiracy theorists -- "She's not drinking the champagne!"

Always leave 'em guessing.