I applaud you for thinking ahead and being honest with the organization you were pledging.
There should be no bad blood between you and any other national organization and as others have said, there is no reason to mention your past involvement. You were not initiated and therefore are not a sister. Joining another panhellenic organization is not a betrayal of any kind.
MAJOR KUDOS TO YOU!!! You were honest and upfront. I am so glad new members are beginning to understand the commitment involved in sisterhood!
I'm sure you'll find sisterhood where ever you go!
If you go through formal recruitment, keep us here at GC posted. We're all behind you!!!
AND, CONGRATS ON ACCEPTANCE TO YOUR TOP CHOICE SCHOOL!!!