He won’t stop smoking around me

My husband is hooked on smoking weed which It doesn’t bother me at all because it helps with his anxiety. My problem is I’m pregnant. He said he was going to stop smoking in our room weeks ago and hasn’t. I’ve asked him about it because I hate the smell as it is and he gets an attitude. I’m not asking him to quit smoking but I want him to stop doing it around me. How can I go about this without creating an argument?