Go through again. It sounds like you were just lost in the shuffle. As long as your GPA is decent and you haven't done anything to make yourself notorious, it's worth a shot.

The only time you're not allowed to rush is if you don't fulfill the requirements (grades, amount of credits, you're a man baby). Panhellenic can't prevent a qualified candidate from rushing because it has no idea what the individual sororities' membership requirements are.

How big were the pledge classes in the fall when 100 girls rushed? That should answer some questions.