[2019] Never bought the game, but it’s in my library some how?

So, I just build my pc and started it up. I downloaded launchers and things. Epic launcher finished downloading so I opened it up and went to the library. Both the early access version and the experimental versions were sitting in my library, despite me never buying them. Now, I did get a key for the weekend thingy back in March, but it got deleted a while ago. I downloaded the early access version and it worked. I didn’t get the time to play so I don’t know if it’s the full version but it was there. Can anyone tell me why?