How can I recover photos deleted from photo booth?

I had a load of photos that I really wanted to keep on my photo booth and was trying to work out how I could send them to a friend.

Then I opened up my Pictures folder in Documents and clicked on 'Photo booth library'. A message then came up with an option to do with default highlighted and I hit enter without thinking.

When I went back to photo booth all of my pictures were gone and it said "0 photos". Have they somehow been deleted? Did the message say that by hitting default they would all be deleted? Is there any way that I can recover these pictures?