A birthing ball is a great prop to use during pregnancy, and despite what everyone calls it, it can be prepared and used not only during labor and delivery. They're also great for yoga, fitness, physical therapy, stretching, and more!
Pregnancy/birth balls can actually be used in a variety of ways throughout pregnancy, labor and even postpartum, and may actually prove to be one of the best purchases you can make during pregnancy. And they're really affordable too (you can find some good ones for around $20-30)!