NOT any of these guys!
Megan didn't immediately confirm the pregnancy Monday night when she hit a Hollywood event, and debuted her baby bump. So, y'know how that can get awkward.
But she just posted shots with 3 of her male co-stars -- Shia LaBeouf, Will Arnett and Jake Johnson -- and said, #notthefather.
So, all signs point to her estranged husband ... despite her filing to divorce BAG.