I finally re-registered on Artground, but the art on it isn't mine! I couldn't get on here for like a month it said i never was a member i re-register and i got 3 pieces of art that are not mine! and watching people i may not watching. I think someone else has used my account

I'd love to hear how this pans out: Bizarre server error, laid-back hacker, or barking-mad user. ... I mean, I'm sure it was one of the first two.

I just deleted them and reposted my own art

I would suggest deleting the art (as you just said you did) and changing your password.

I got aswell. The art from my other account is now under the username Raine But, the stuff in my new account wasn't mine, so I deleted it. >o< But its all fine now.