My password on boot up i thought included an @ but it includes a ". When i try to change it once the Mac is on it says it's changed but on boot up it requires the latter again?

My password on boot up i thought included an @ but it includes a ". When i try to change it once the Mac is on, it says it's changed but on boot up it requires the latter again? I think this is because i changed the keyboard to British PC but why won't the change happen so that when i boot up it changes as when i go in to profiles and change my USER password it says it's an @ already but when i turn it on it needs me to put in the " ??? Using a bluetooth wireless Apple Keyboard