Jan Scoop Neck Column Gown

I am 5'5 145 and originally had the size Medium in my cart, but read on other styles of Birdy Grey that the dress ran large, so I purchased a size Small. The dress is all over very strechy, except for the band around the waist, which has zero stretch and when the zipper hit that point in the dress, I was unable to zip up fully. The dress has built in cups which were nice, but they seemed a bit low and gave the look of saggy boobs. Overall, the dress was nice, color was beautiful, pockets were convenient and the back of the dress was stunning. I might try ordering this dress again in a Med just to see for fit, but not sure it will help the check area?