You can try the following: Babies, Juno, Knocked Up, Baby Mama, Away We Go, Business of being Born, Baby Boom, Neighbors, Nine Months, First Comes Love, Waitress, Look Who's Talking, Life as we know it, 40 weeks, Bridget Jones's Baby, Father of the Bride part 2, Storks, What to expect when you're expecting, Junior, The beginning of Life and baby boss.
OMG so many! Back up plan, Juno, What to expect when you're expecting, Nine months (Hugh Grant!), Baby Mama, Knocked up.
juno? hahaha that's the only one i remember having someone pregnant in a movie
Tina Fey and Amy Poehler's, Baby Mama
The Backup plan is quite funny!