I agree with Adele. Even if you did get your tdap, 12 days is way too soon to take a baby out amongst so many germs. Their little immune systems aren't even built up enough yet. I wouldn't do it either.
I had my tdap shot and I probably still wouldn't take my baby out at 12 days, especially if there are cases of whooping cough around. I just don't think it's worth the risk. . But it's just my opinion. .