Unexpected

Someone calls your work and leaves a message to tell you she is pregnant. The mystery caller doesn't leave a name, so your coworker Kate tries to help you uncover who it was as you recall the events with the different girls from your recent past. Soon the two of you become detectives as you work out the case of who you've knocked up. It doesn't help when you don't have the phone numbers of your one night stands, and the girls you thought you were on good terms with aren't answering their phones.