I guess it all depends on how you look at it. At the beginning of the movie when the sorority girls are being introduced, They say they have 7-1/2 girls there, and when the shorter girl objects and says, "Hey," she says she was sorry, but she meant Harmony. I assumed that meant they were both pregnant, but since it's never referenced again, apparently maybe the joke was supposed to be the extra 1/2 was because she was heavy, not because she was pregnant, which is a really bad joke. It would be much better if they meant because she was PG.