My computer has no password, but it just locked me out, what do I do?
My computer shut down due to low battery. When I plugged it back in and turned it on, it asked me for a password. I have no password on my computer but it's saying I have one. I've tried every password I've ever used on my computer and it won't work. It then told me I can use my apple id to reset my password, but when I tried that it told me my credentials were wrong. They're not, obviously, because I logged in here no problem.
What do I do?
I can't reset my computer because I've haven't backed it up in awhile, and I have many things on it I can NOT afford to lose.
MacBook Pro (13-inch Mid 2009)