Blowjob & teeth

How can I tell if I’m using my teeth when sucking dick? Like I’m pretty sure I’m not and my boyfriend has never complained or reacted in a bad way but idk. When I smoke weed and then suck dick I get soo paranoid that I keep using my teeth and now I’m wondering what if I am. Like yesterday he started thrusting himself in my mouth and I kept feeling like he was scraping against my teeth but idk