Depends on chunk size and what you are hiding
You are giving away 1/4 of your data in (hmm, let's say) 32K chunks.
If you have a file smaller than 32K, then there is a 1 in 4 possibility you have handed it to someone else. If you have a database, then you have handed bits and pieces.
If you are mostly sure it is OK, but not CONVINCED, please the drive on a linux box, and (assuming is is /dev/sdb) (and you want the 1st partition) execute the following (change the 1 to increment partitions):
dd if=/dev/sdb1 | strings | less
It'll dump the drive and let you read any text. You may find enough recognizable things that disturb you and make you want to treat it a bit more securely.
