Help! How to avoid drinking..

I need some advice.. You know how everyone has that "bad influence " friend.. The one that's always ordering or pouring another round of drinks and shots... The one that never turns down a shot.. Well I'm that friend..
 We are 5 weeks pregnant and I need advice on how to avoid drinking with my friends, without telling them I'm pregnant. 
With New Years and then my birthday soon after we also have friends visiting from out of state and staying with us. That means going out to dinner, brunch, and bars together. We have been planning the bars we are going to since before I even got pregnant!