It is generally recommended to plan your maternity photography session in the late second or early third trimester (27-32 weeks). You want to be clearly showing but still feel comfortable enough to enjoy the process.
Earlier than that and the belly may not be prominent enough, later than that and you may feel uncomfortable. But every woman and every pregnancy is different, so listening to your body is always a good idea. Be sure to plan things early so you’ll be sure to have your choice of a convenient time.
Wear one of your favorite maternity outfits! Something comfortable and flattering to your form. A relaxed fit is good since you’ll be moving into different poses. Midtone colors work best — avoid busy patterns which can be distracting. I also suggest bringing a black and white shirt if you have it.
I can also provide an assortment of fabric wraps to accentuate your form. The wraps give a more intimate look while keeping things completely discreet. Bring any items that might be important to you and your baby. Sonogram photo, little shoes, blankets, etc.
Don’t forget to bring dad as well. It is nice to have a mommy and daddy portrait awaiting their new special bundle of joy. Bring him a black and/or white shirt as well.