While I think a pregnant belly is beautiful, I know some women aren't comfortable having it all hang out. So if you are someone who wants some coverage over the bump, my best suggestion is to buy maternity swimsuits.
I know, I know, none of us wants to buy swimsuits we will only wear for one season but take it from someone who has been pregnant over summer with all five pregnancies; the best way to cover your bump comfortably is to buy a swimsuit designed to it.
Maternity swimsuits are designed differently to allow your belly to breathe while not stretching out the rest of the material. I remember shoving my big pregnant belly into my favorite one pieces just to have it completely stretched out when I tried to wear it postpartum. Chances are you will wear this again postpartum! I tend to wear my maternity clothes for quite some time after having a baby.