You look great! I bought a few things in bigger sizes from the thrift store to get me through the awkward "too big for my normal clothes, not big enough for maternity clothes" phase. I found some fairly cheap, versatile maternity items at Target and Old Navy. I was lucky that I got a few pieces from a friend to give me more options. However, since she is about 6" shorter than me, it was only the tops that fit, all the bottoms were too short.
Like Ornella mentioned, I had a black dress that I wore all summer long with different shoes and accessories. It was loose and comfortable in the heat, but nice enough for the office.