Am I overreacting ?

So me and my boyfriend have been together for almost 6 months now. We've gotten pretty good at knowing each other and we get along really well. We're 22 and 24. He's a med student and almost graduated. Besides me, he has a very close friendship of 8+ years (I've met them multiple times and they seem to be very cool) and they occasionally get together to hangout at each other's appartment to play board/video games, you know...guys things. The ONLY problem in this situation is that they also like to smoke weed together from time to time, just for fun & relax. Now, I don't know for sure if I'm really THAT against weed, because I kinda am but in the other hand I'd like to try it too some day, but overall I don't like it personally for moral reasons. I've mentioned that to him and he said he's fine with it and he would never smoke with them when I'm around. I told him not to smoke even if I'm not around cause it's something I'm not quite fine with.

I know he felt kinda pressured, especially with the fact that I drink alcohol quite a lot (which doesn't bother him for as long as I don't abuse with it, he personally doesn't like alcohol, he only has a beer here and then)but I do drink a lot of wine and other alcoholic beverages (not to the point of getting drunk though, the most I get is tipsy, especially since I'm used to alcohol for over 6 years).

Now am I overreacting? Everytime he hangs out with his friends I get paranoid that he's smoking. It really messes me up...😩