Phone dead for 3 days & then reset to an old backup - have I lost anything?

[MichaelBanning]

My phone got a BSOD on the 23rd, and I wasn't able to reformat it until the 26th. And then when I did reformat it, the only backup listed that I could use to recover everything was from a month ago.

My question is what, if anything, did I lose while my phone was dead and/or from having to reset to an older backup profile? Text messages? App data? I'm kinda freaking out that I may be missing stuff, but I don't know what it might be.

 

[Horvath Gyorgy1]

First of all: what phone? From what operation system did it go dead?

 

[MichaelBanning]

Nokia 1520 on Windows Phone 8.1