Thea Clayhill (Lindsay Lohan) is about to lose her position as secretary to a very cranky publisher (Chris Parnell) -- so she lies about being pregnant to save her job, as she saw on an episode of Law and Order that it is discriminatory to fire a pregnant woman. The plan works, and she gets to keep her job.

With the help from a friend (Cheryl Hines) -- and a pillow -- Thea fakes the pregnancy while she figures out her next move. In the meantime, her boss gets called out of town and his cute brother Nick (Luke Kirby) takes over. Nick launches a new parenting division at the publishing company, and he wants Thea to be the editor. This results in a raise and promotion for Thea, as well as the beginning of a romantic relationship between her and Nick. She begins to enjoy her life to the extent that her "pregnancy" becomes real to her. However, her little sister soon grows frustrated with the lie and destroys her pregnancy pillow in a fit of rage. Quickly, Thea grabs a balloon, which pops, thus blowing her cover.

Soon, Thea gets herself together and apologizes on a national talk show to Nick and the company. Nick forgives her and takes her back, and she gets to keep her job. Two years later, Thea is shown going into labor with her and Nick's child...for real.