USB Stick not working

[Arndriod]

Hello,
This morning I wanted to make a backup of my USB, since it was serveral days I haven't made one. So when I put my USB stick in the computer, it gave the message that my USB is not formatted and need to be formatted. I don't know how this happened, because I always remove the stick with safe way. And I tried to open de USB stick from another pc and it gave me the same message. There are some important documents on the stick which a made yesterday 

I also tried to check it on errors, but that gave an error.

Is there a way to solve this problem without to format? Or are there other solutions?

Greetings,

Arnie

[patio]

You could try Recuva on it....

[Arndriod]

I tried Rucuva on it and some other recovery programs, but they don't find anythink on it. And one of the programs I used didn't reconize the FAT file system... Is there anything else I could try?