Nothing will happen. How can they prove you have the 'stuff' in the bag. The bag could have come from anywhere and belonged to anyone before.

All you need to say is I dont know who owned the bag before me, err....found it at work and used it to keep my money in when I go out as I keep loosing it.

It may of had the 'stuff' in at some point but not when I had it.

nothing to worry about..........