Account login activity says I’ve been logged in to 20+ devices, only 3 of them were actually mine.

So I was just randomly checking my security when I saw that I’ve been logged in to 20+ devices. Among which, 3 were my devices but others were from different places from my country to which I’ve never been to. Others says it’s from an unknown device. I’ve already logged out from those suspicious devices as of writing. Was I hacked? Or some glitch? I’m really worried.