I have a sharp pain in my lower chest in the middle of my breast when taking a deep breath or when lifting up my arms?

Chest pain: Most of the time pain with a deep breathe or moving arms is either from the muscles of the chest wall being sore or the little muscles between the ribs being sore, or a sore area in the breast itself. If you press on the sore area gently and it hurts its more likely the breast. If its not sore until you press harder it's the chest wall. Rest, heat, might help. If not better in several days see dr.