Odd bellies question

I picked up a trio of female Ball pythons a week or so ago in a trade for some of my Corn snakes. My question is, do normal BPs ever have clear, un-checkered bellies? All three of these girls have very clean bellies, and one of them even has the side checkers like a Yellowbelly would have. I'm pretty sure they're just normals (though I do plan to do some breeding trials with them), but I've never seen normals with clear bellies before. All three of my other normals have the mottled, check bellies. Here are a few pics:

Bastet

http://i777.photobucket.com/albums/y...psc44cff55.jpg


Nephthys

http://i777.photobucket.com/albums/y...psbc77a920.jpg


Sekhmet

http://i777.photobucket.com/albums/y...ps5c323ac4.jpg

Nice looking normals:snake:f

Bellies on normals are variable from busy to clean.

Thanks! :) I just have never seen normals with clear bellies, so I wasn't sure if they had something else going on with them. I appreciate the input and compliments.