Goofs

When Alison is weighed in the doctor's office, her earrings change from stones to gold hoops.

When Alison is sitting on the couch next to Ben as his friends leave to go play paint-ball, she has a noticeable pregnant belly. In the next scene, she is sitting on the side of the pool in a bikini with her sister and nieces, and her stomach is flat. In the next scene, the belly is back. (According to the Director's Commentary, the fake belly couldn't get wet.)

When Alison talks with her boss and Jill about her pregnancy, a mirror behind her boss shows a TV behind Jill. In the close-up shots of Jill, the TV is gone.

At dinner, when Pete does his Robert De Niro impersonation, his wine glass is in his hand, then on the table, and back again.

When Ben is watching Cheaper by the Dozen (2003) on the TV, the film skips from a scene near the beginning, in which Tom is getting all the kids up for school, to a scene near the middle, in which Tom puts a band aid on one of the girls and fishes an athletic cup out of the pasta.

The ultrasound images do not correspond to stated gestational ages. They're off by many weeks.

In the bar scene in the beginning of the movie, Ben helps himself to two Coronas. He then hands them to the ladies. However, Coronas require a bottle opener, which he never used.

Ben and his friends are creating a website that show female nude scenes from movies. Since the nude scenes are part of copyrighted films, it would have been impossible to upload them to a website without permission. It would be illegal.

However, the only detail Ben goes into about the website is that it will provide information on the movie title and exact time (hour and minute) into the movie that an actress appears nude. That information is public knowledge. Anybody can gather it simply by watching the movies. The website is really just a glorified spreadsheet of movie titles and time stamps. Ben says nothing specifically about uploading the actual scenes.

Alison's red VW has no rear view mirror and no front head restraints, which is illegal in the U.S.

In the birth scene, the umbilical cord of the infant is not attached to the infant's stomach, and the infant's completely healed belly button is seen next to the cord.

When Debbie and Alison are looking at the tests, Debbie picks one up and starts freaking out, thinking it was the one she took because it says positive. The result window is pointed toward the camera, not toward her, so she wouldn't be able to see the results.

When Alison is arguing with Ben in her car, there is no rear-view mirror installed on the car (presumably to give the camera a better shot of them).

Alison has prominent tan lines on her shoulders when she first starts talking to Ben at the birthday party near the end of the film. These are covered up with makeup a few minutes later.

When Ben and Pete are at the record store, the rows of albums in front of them are not organized in alphabetical order, although it's possible the owner/manager of the store doesn't care, or a previous customer put the albums back incorrectly.

When Ben and Pete are in the Las Vegas hotel room, the Sands Hotel is seen out the window. The Sands was imploded in 1996 to make way for the Venetian.

Some of the characters talk about seeing Spider-Man 3 (2007), which came out in theaters four weeks before this movie did. Later in the movie, Allison interviews celebrities at the 2006 MTV Movie Awards (2006), which took place a year before the movie actually came out.

When Ben is walking up to the door for Debbie and Pete's oldest daughter's birthday party, he stops to knock. A crew member is reflected in the door, walking up beside Ben with the camera.

When Alison is in her boss's office discussing her pregnancy, a small microphone is briefly visible in her cleavage.

At Del's Saloon, the camera and crew are reflected in a passing minivan.

When Alison and Jill discuss Alison's pregnancy, a crew member moving around is reflected in the office window.

When Ben and Pete are headed to Las Vegas, a wide shot shows the car approaching Vegas from the east. They are coming from California, so they should be approaching from the West.

When Alison and Ben drive home with their baby, they pass the same scenery, including a McDonald's restaurant, more than once.

Ben claims that he was so drunk that he doesn't remember the night with Alison and says that he wishes he did. Yet later he and Alison argue over the fact that he didn't use a condom, and Ben clearly seems to remember being told to "just do it already."

Debbie pulls up a map of sex offenders, and talks about how they are surrounded. The film takes place in California, but the map shows Boston (Interstate 95 and 93 intersect with routes 128, 1, and 3).

In the club after Ben and Jason go to talk to Allison and Debbie, Jonah tells Martin that he has to leave. A few scenes later, he is still in the club.