If the database is not in Filemaker Documents then it would have been delete. The file would still appear in the Documents of filemaker go even if the file was corrupt. If you are looking for the file on your iPad, make sure you tap the Device icon and not the Recent icon. It can be missing from the recent and be listed on the device.
If you backup your phone to icloud then you may have a backup, the only issue is your backup would only be as new as the last backup to icloud.
It is a good idea to make multiple backups before doing anything with your file. It easier to transfer files to and from your device using dropbox and it is also a good place to have a backup. Dropbox has a free account and the apps for your computer and ipad are free.