If this happened, chances are you will have already deleted these photos off your digital camera, had a new mobile phone, and not backed them up to physical media or other cloud storage. People don't tend to print photos out and put them into albums anymore either. In this unfortunate scenario, all your photos would be gone, with no way of getting them back.
Good news, there is now an app in Facebook where you can save your photos (all albums, selected albums, photos you are tagged in) to your computer. This can be found here https://www.facebook.com/DownloadPhotos. Click on the Go to App button to get started.