Congrats on day 45 Zlh. That's a huge accomplishment! I think with time, it gets easier to tell people that you just don't drink. Simple as that. The first few times I went out on business functions after I had quit I felt a bit uncomfortable. My usual response to being asked if I want a drink was that I am cleaning out my system for a while, or simply no thanks. Usually that is all it takes. I always made sure I had my non-alcoholic drink of choice in my hand at all time.
The bottom line, is that you are doing great. If there is any way to avoid these situations until you feel more comfortable, I would do so. Take any advantage to give yourself as much time as possible without forcing temptation.
Most people in social settings could care less what you are drinking.
Stay strong for yourself! Congrats again on 45 days.