locked out of laptop says password is incorrect

I have a HP Pavillion laptop 15z-ab000CTO with Windows 10. I don't use it all the time since I also have a PC. Last time I used it was about 3 weeks ago to update anti-virus protection, do a scan and performance items. No problem logging in then. Tried to login to laptop last week and I keep getting 'password is incorrect' even though I know I am entering the correct password; this password is to unlock the laptop itself.
Every one in awhile, I will see 'welcome' after entering password, then once again, password incorrect shows up almost immediately. When I set the password for the laptop 2 1/2 years ago, I did not make a disc when doing so, so I cannot reset the password either. I am not super computer saavy, so any help I can get would be appreciated but it will need to be explained to me in detail. Thank you.