Should I ask employers if there’s a background check?

So something devastating happened to me a while back. I got a job offer and they required a background check. I had a mischief charge a few years ago but it got withdrawn and I paid back restitution. Anyways they asked and I thought it would be fine but my background check came back inconclusive. I absolutely freaked out and discovered that I would need to have a File Destruction, as the paperwork of my non conviction is still there. Anyways, I am currently in the lengthy process for that but was wondering if it’s appropriate to ask employers if they conduct a background check, or would that not be a good question and bring negative attention to you?

It’s awful because I didn’t even get convicted but feel I was still treated with discrimination anyways. Any advice on this is greatly appreciated as it seems to be effecting my life now and job prospects. And my charge got withdrawn.

Also I’m in Canada so hopefully I’m allowed to post here with terminology that’s understandable to the US. Thank you and I appreciate your help.