If you were to look through my closet, these are the staple items, brands, and clothes I currently love.
I am in my seventh month of pregnancy and it is getting harder to get dressed each day. The belly is really growing, which is a good thing, but makes it more difficult to know what will look good each morning.
I am a little taller than average and am mostly wearing things with elastic bands (lots of stretch) and maternity clothing. I prefer skirts and pants with the under belly band, instead of the over-the-belly elastic/spandex. I have found some wonderful maternity lines though and am really happy with my current collection. If you are petite, I honestly think you have more options, as maxi dresses and going one-size up in regular clothes still probably look good on you.
My advice would be to stick with neutral basics and then add fun accessories! You can purchase print tops and colorful dresses. If all your pieces coordinate, you have many more options. For the basics, I recommend one pair of leggings, jeans, capris, a pencil skirt, and a pair of shorts. Once you have that covered, you could order fitted dresses and maxis to complete your maternity closet. You can mix and match your tank tops, tunics, and favorite NFL team henley with your basic bottoms and not get bored with your wardrobe. Plus, you can do this affordably with reasonably-priced bottoms and tops, and then spend a little more on your dresses.
Since it is summer and a bit more relaxed out here in California, most of my separates are more casual for weekend wear. My dresses could be worn at work, to a fancy function, or on weekends. For dresses, Madeleine Maternity is my go-to. Isabella Oliver and Seraphine also have nice dresses. If you are looking for more formal, business clothes, I would recommend Nordstrom and Loft. For affordable maternity options, I would recommend Target, Old Navy, Gap, and Asos. Most maternity lines have the best selection online and some are sold online exclusively.
If you will be pregnant this fall and into the winter, you will probably want to invest in a warm winter coat and a few sweaters that really showcase that growing baby bump! Good luck planning your maternity closet and enjoy this wonderful time!