nothing wrong in showing off a little bit of bump, pregnant women look so cute.
I have to agree with Saadia, Shirin and Anchal. There's nothing cuter looking than a pregnant woman with a smile on her face.
Modesty is important and should never be overlooked but unfortunately some folks confuse modesty and shame.
Depends on the culture you live in. Mostly in the west showing the bump is cute, actually decent & something to be proud of. Not the case back in the east ...
I guess its similar to take your dupata on your head when an elder (especially male) comes in the room. In the west no need but in east not doing so will be consider disrespectful.
Maybe the question should be, "do in Rome as the Romans do" or "Hang on to your traditions and roots"