I´ve been working in a model for almost to weeks now, and I have to finish it before tomorrow for school. Last night I was working on it just fine, but this morning I oppened it, it says the last time it was modified was last thursday. Please help I´ve lost a whole week of work and I´m going to fail my class. I´m sure I saved it at least yesterday and the day before.
Are you using SketchUp Pro as your profile says? Or are you working online.
Sketchup pro
So this is a problem with your hard drive file organization. The options are that you have been saving it somewhere else on your hard drive without realizing it or that you moved it into your recycling bin. I know very little about Windows but I assume there is some sort of search function to look for files on the HD with the same name.
You could try opening SketchUp and go to SketchUp>Preferences>General and tick show welcome window. Then close and reopen Sketchup. When it starts there is a list of recent files in the welcome window.
I already looked for every .skp and .skb files and didnt find it and in the welcome window is where I can see my file but it says: last modified november 5. Thank you but I´m already losing hope now 
Weird. Is it possible you have two versions of SketchUp active on your computer? But a file from another version would still show up in search for .skp. Sorry, good luck.
hello, since 2019 version, autosaved files have changed of location. have you looked there ?
paste C:\Users\%USERPROFILE%\AppData\Local\SketchUp\SketchUp 2019\SketchUp\working\SKETCHUP\RecoveredFiles in explorer address bar