Second hand smoke

I was at a party with my parents and people were smoking. I stayed away from all cigarette smoke as best I could. After awhile someone got a little ballsy and started smoking pot. I told my parents and we left right away. The party was all outside, but being I was around it for about 2 or 3 seconds, I want to be sure my child is safe. Would that harm the baby? Could I test positive from minimal second hand? I'm 15w3d. I've never been a smoker and stay away from it all together. I'm sure I'm being a paranoid momma, but my baby comes first, so I'll be paranoid...