Should j just suck it up

I'm around 7 weeks pregnant and am going to spend New Years with my boyfriend. He has a friend who always has parties which involve drinking and smoking and other drugs. I don't like being there at all and I need to stay away for our baby(he doesn't know yet btw). He said he doesn't have to go and we'll just stay home but I can tell that he really wants to go however he was just at a party there on Monday. Should I just suck it up and go with him or no?