Maybe it's hitting you in your chest and you accidentally gulp down choking xD. I dunno, but don't swallow your smoke. Inhaling does a good enough job getting it to your lungs. I dunno about swallowing smoke but I always thought it went to your stomach then. I don't know but I really don't care because it's nothing something I do and 99.8% of the people I know never mentioned anything about it. Besides you and some other guy lol.