The best way to tell if your bra is not fitting properly is to try on a few different bras and see which one gives you the most support. If you are wearing a bra that is too tight or too loose, then it may be time for an adjustment. The first step in adjusting your bra is to take out the old band and put on a new one. This will make sure that both of them are the same size so that you don't have to worry about sizing issues later in the process. You should also make sure that your breasts are filling out all of the cups evenly. If they are spilling over or sticking out, then it's time for a change in size or style.