There was nothing dangerous in what you did. The BP was far enough in to allow the gun to operate. All that could happen is perhaps a little increased blow-back. In my opinion, you'd have to leave the BP waaaaay out before it could ever come back at you and cause injury. So far out that the gun would have no chance of being operable.

If it makes you feel better, leave the BP out of the gun after cleaning, and only install it when ready to go to the range or hunting.