The same thing happened to me and I lost over 200 photos. I downloaded a data recovery app from the play store (don't remember which one though) and I was able to get them back. The only problem was the quality was a little degraded. I didn't care as long as I got those photos back. Just letting you know it is possible. Just be sure to do this as soon as you can because every new picture taken or new app installed writes over the space where something was deleted. Hope this helps.