Wearing two piece while pregnant?

It's already getting hot here in Arizona  and it's almost time for swimming weather. I wanted to go shopping for a cute bikini but my mother was appalled to learn that I wanted to wear one while pregnant.  I'm not a big person by any means, but I feel like I shouldn't be ashamed by my new bigger body and show it off in a cute bathing suit. What do you guys think or what have you done in the past?