Is it normal to have a choking fetish?

I look like a tween but I'm 18 and I'm pretty short too which doesn't help with people confusing my age, but that's one of the main reason my bf loves me.
But last week during sex, he started to choke me a little just before I was going cum.

I was shocked and questioned him later. And he told me he had a fetish for the action of choking, wether a person is getting chocked or they're chocking during oral sex like during a bj. He's very dominant in bed but I didn't expect this.

Is this a normal fetish? Should I be concerned?

P.s I'm a bi male (so people don't get any surprises later about my gender.)