Job interview in third trimester

I have a second-round interview for a job I really want and I'm in my third trimester (and carrying huge).  I told them before the first-round that I was pregnant, so it's not a surprise, and they called me back, so that's great.  I have no idea what to wear.  For the first interview, I had the perfect little black dress but I can't wear it again because there will be overlap of people who saw me the first time.  I feel that buying a maternity suit that I will never wear again and that makes me look like a big balloon is kind of silly.  I have a black wrap dress that I was thinking of wearing with a crisp long-sleeve white blouse underneath with black kitten heels.  Does that seem okay?  It's for a marketing job for a school, but the people interviewing me will be part of the board of trustees and who all come from New York City law firms or other businesses.  I'll be the only woman in the room and I feel (hope) that I may get a pass for not wearing a suit because of the pregnancy thing.  What are people's thoughts?