I was one who didn't put on too much weight at all & found I was in my normal clothes for some time. Esp the skirts, or I could buy what I normally would just a size up. This was cheaper than maternity clothes & found a lot of maternity stuff was just way too big for me.
Skirts with elastic are great, I still wear many of mine now. The current fashion is really good if you are pregnant, lots of babydoll tops that would go nice with a pair of black pants. Black pants are a must, & I would go for ones that are not too long as you prob will not want to be wearing heels too much. The smock top/dresses are great too & all can be dressed up with a nice belt.