If you removed the beta profile before you received the iOS 12 update, then you should have gotten the final version. iOS 12 (16A366). You can verify the exact version in Settings->General->About->Version
If you had the Beta Profile when you updated to iOS 12 then you probably just have the GM (Gold Master) iOS 12 which is essentially the last beta release before the public one, and for all intents and purposes is the same version as the final release.
tward1969 wrote:
"If you keep the Beta until the official iOS 12 is released you will have the choice of updating to it as long as you have not updated to a post iOS 12 Beta before that. i.e iOS 12.1 Beta or something.")
Beta testing never stops, there's always a new Beta version. If a 12.1 beta version had been released (it hasn't) before the final iOS 12 public release hit, then you would have been at a newer version technically. So would not have been able to update to the final iOS 12 release.
At this point, you are at the final release of iOS 12.