Question:

A maternity bra is constructed to better fit and support your maternity shape than a regular bra. It usually will come with wider straps for extra support, and more material in the cups for extra coverage. Several rows of hooks or fasteners in the back will allow for the rib cage growth that you will experience during the course of your pregnancy. You should buy a bra as soon as you are no longer comfortable in your non-maternity bras, and you should size it so that it fits you on the tightest hook, so that you can get more mileage out of it as you grow.

A nursing bra should not really be purchased until the last month (or few weeks) of pregnancy, when the size of your breasts is closest to when your milk comes in. A nursing bra typically has a few hooks, or velcro, or some other type of fastener at the top of the cup for easy opening, and the ability to adjust the tightness of the cup. Some styles are just meant to pull off to the side. Some even come with pockets to hold nursing pads. Whichever style you prefer, be sure to get a good fit. A nursing bra that is too restrictive may clog your milk ducts and interfere with your milk supply.