Yes. That will happen sometimes when only using "Save". That is why it is better to do a "Save As" for each significant project "milestone". Like you get your drums down, "Save As". You get your bass down "Save As". Etc.
Just using "Save" is hit or miss because if a crash occurs then SOMETIMES you can get your project back or at least to a certain point but IME you are just as likely to lose everything (mind you I haven't been in that position since X2 which taught me to be hyper vigilant about manual project versioning via Save As).
Also even if the project DOES survive something made it crash and I find those recovered project tend to be at least partially corrupt and will generally just keep crashing and getting buggier and buggier until they are useless. By going back to a stable Save As version you avoid that.
Now the "Auto Save" feature might work better because you can go back through auto saved versions to maybe get a version before the crash/corruption occurred but I've never enabled auto save. I'd rather do it myself so it's not some random save point I'm returning to and it doesn't sound quite as reliable as manual project versioning.
Yeesh... I'm back for an hour and endlessly prattling on about "Saving". lol
Oh well.
Also, check your project folder if you haven't already. Maybe there are some files in there you can recover. If you are using the "Start Screen" to access you projects be aware that it does not always display the most recent version of a project. You have to go to "File > Open" then navigate to the actual folder where the project is stored to find it. Essentially the "Recent Projects" thingie in the Start Screen (and in the RP section of the File menu) is unreliable. That's why I ALWAYS open directly from the ACTUAL project folder unless I am certain the Start Screen is displaying the project I want.
So yeah... get theee to your project folder. Your project may be there. Maybe not.
Cheers.