excuse for not drinking

I have a team lunch on Thursday- about 9 people - to celebrate our accomplishments through the 1st half of the year.  Everyone always says how boring department lunches are, cause no one ever drinks, so this is setting where people order bottles of wine (or whatever) for a nice meal together.  I'd normally have a few glasses of something...except I'm 7 weeks. A larger team had a happy hour last week (had to go, office politics) and I managed to say I was thirsty, so just was going to start with a club soda, then I left shortly after.  I got some funny looks, and someone asked if I was still nursing my daughter (which I stopped doing a year ago), so even that was noticed.  The timing couldn't be worse.  Haven't even gotten together as a team since Christmas, and now two drinking events in one week.  I'm not sure I could just order something and not drink it cause it would be noticed.  Not sure if they'd fall for the antibiotic thing...and certainly not the "I drank too much last night" or "I'm on a diet" (I like food and at least want to enjoy the lunch!) Help!!!