Do I have carbon monoxide poisoning?!? PLEASE HELP?

The other day i was sitting in the kitchen and a burner on the stove was turned on but there was no flame. I sat in the kitchen for 30 minutes with the burner on but with no flame until finally my sister came in and said that it smelled really bad. I couldn't smell it because my nose was congested. My question is was the burner leaking carbon monoxide or was it leaking natural gas? and would sitting next to it for 30 minutes breathing it in cause any damage to my brain in any way?