Traveling to Paris

My husband and I will be going to Paris for a week in September. Very excited but now I have to buy 2 evening gowns (work galas) and a new wardrobe, I live in the south (US) and its 99 today so as you can assume, I don't have many clothing items for "chilly" weather.
Where can I go to buy new CUTE maternity clothes without breaking the bank? (I'll be 25 weeks) We have 4 girls already so I don't buy clothes for myself much! Any help would be appreciated!