Mac-mini won't accept my password

It worked fine yesterday, I enter my password many times a day because I install and remove apps often, so I've not forgotten my password, the keyboard may be faulty I suspect... How can I see if the keyboard is typing the password in incorrectly?

I'm going to just swap keyboards I think, but the tax on users that thieves place on us is getting a tad much. I'm the only user on this mac, (I think, because I cannot see other users icons on the login screen) and I do not have a recovery key because someone else provisioned the mac for me. Hope it's just keyboard pain.