I don't get too many negative comments either, at least not regarding this baby. A couple "wow, you're going to have your hands full" (but um, have you met my kids? It's true! LOL!), but nothing rude. I do get a bunch of "how do you think your daughter will handle it?"...likely because she's adopted, and there are people close to us that know she has attachment and anxiety issues.
I know the people at my church have been waiting for a pregnancy announcement since we lost Ryland--they spent the past 3 years speculating about whether I was pregnant again. So I messed with them and hid this pregnancy until I was 20 weeks along--lots of sweaters, coats, etc. So they were quite surprised when one day I was huge. LOL!
I got more negative comments with my first--I was 23 and looked younger than that so people assumed I was another teen pregnancy. I would have thought this time I'd get more rude comments because I have 2 children already (of different races obviously) and I haven't been wearing my wedding ring the entire pregnancy because it's not comfortable with my puffy hands. I do get a lot of double takes, but that's about all.
ETA: Oh, I do remember one thing...I got quite a bit of "I know tons of people who were infertile and got pregnant right after adopting". I always just respond "what makes you think I had fertility issues?"--it's true--we didn't adopt because of infertility. *Getting* pregnant was not a problem for us. Bringing the baby home at the end was.