They nail this one. Check it out (don’t be sipping a beverage, you’ve been warned)

The Editing Room – Star Wars: Episode III – Revenge of the Sith: The Abridged Script:

“NATALIE PORTMAN
(yawning)
Hayden, I’m pregnant.

HAYDEN CHRISTENSEN
(furrowing his brow)
How can you be sure?

NATALIE PORTMAN
Because in a minute or two I’ll
actually be showing. Really.”

(warning: spoilers! It’s a script, dammit)

Link found via I Don’t Watch Movies, who also has awesome reviews and thoughts on a wide variety of movies (and not just Star Wars, JaG)