disappearing dogs :(

[snowmitts4]

I logged on the same as usual one day and my entire save file was gone. It didn't even give me an option to open it or a notification of a corrupted file. It was like the file was never there, even though I had played it just a couple days prior. Is there a reason for this? I opened it the same way every time and had it on the same account, no different devices, etc. Nothing changed.