Hands down, the most comfortable maternity clothes I wore were my Old Navy Maternity Roll-Panel gauchos and skirt! I never invested in the pants because it was just too hot in the summer!
The material is pretty light weight and very stretchy! I like the roll-panel waist because you can fold it up or down to have the waistband sit where it's most comfortable for you. I really like the versatility of these pieces. You can dress the gauchos and skirt up with a nice blouse and fancy shoes or throw on a tshirt and flip-flops for a casual look. They use to have a ton of colors, but it looks like the selection is a little more limited now. The pants are $22.94 and the capris, gauchos and skirt are $19.94 each. Right now you can use the code ONSAVE20 to get 20% off! I still wear my skirt, but the gauchos are a bit too baggy in the legs now that I've deflated! :)