Important: does your bra pinch?
A bra should sit properly , not just for aesthetic reasons, but for health reasons too. A D-cup breast is quite heavy.
Unsurprisingly, badly-fitting underwear can lead to health problems.
Bra straps that cut into the shoulders can affect underlying nerves and muscle tissue and cause pain in the neck and shoulder area, and even in the arms. A too tight underwire can cause unpleasant hardening and pressure points. The underbust measurement must be exact, as you might otherwise have to deal with tension and back pain.