Am I still on iOS 13 beta? I have an iPhone XS which I updated to iOS 13 beta on early August (perhaps around beta 5) and I have been receiving updates. 

At this moment, I think I should have received iOS 13 stable already but I think I haven't. 

I think I'm still on the beta release and want to know how I would get on a current / stable build of iOS from here.
Yes, you're still running beta software (at this point in time 13.2 is a beta version).

You can remove the beta by following Apple's instructions here:

https://support.apple.com/en-gb/HT203282

The easiest method there is to open Settings &gt; General, tap Profiles &amp; Device Management, tap iOS Beta Software Profile and then tap Remove Profile. Afterwards you need to reboot the phone.

Now the next time Apple releases a non-beta version of iOS, you'll be able to update to it from the normal Software Update.

If you want to remove the beta right away and install a non-beta version, you'll need to erase and restore the device. You'll want to ensure that you have an up to date backup before erasing, and then restoring from that after restoring the system.

The easiest way to do this is to connect your iPhone to your computer, and then put your iPhone in recovery mode (press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the side button until you see the recovery mode screen). From iTunes (or Finder if you're on Catalina) choose to Restore the phone, which erases the device completely and installs an up to date, non-beta version of iOS.