If your females have looked the same for 2 weeks, then they are not pregnant, or at least the bulge you were seeing 2 weeks ago was not a bulge caused by pregnancy.

Take a look at this pics in this thread. There are a couple of pics of a very preggo girl who is about to have her babies, and in another pic, there is one female that looks like she is just starting to show.
http://www.ball-pythons.net/forums/s...ad.php?t=86739