FileVault says an recovery key has been set that I dont remember doing (filevault is off)

I have a macbook air running high sierra and filevault says a recovery key has been set that I dont remember doing. I even checked keychain but when I tried to unlock it no prompt came up asking my password. How can I change my recovery key ?. Again, FileVault is off, I didin't forget my password either (My account is an admin and I just now changed the password) and keychain says the certificate is expired.