Several PDFs got deleted

When I'm at school I don't have internet connection on my iPad. Usually when I'm offline, I can still scan documents and they get uploaded in the Cloud automatically when I'm reconnected to the Internet. But last month, I scanned two documents while being offline and when I started the app with an internet connection, they were gone. Is there any chance I can get those scans back? I had to return the original documents und now don't have a single copy of it!