What is causing my left ring finger to feel weak and numb and pain in my upper left arm/shoulder

I have been having sharp stinging stabbing pains around the left breast area and get achy throbbing pains in my left shoulder and upper arm area, and to add to the fun my ring finger on my left hand gets weak and numb with an occasional twitch. I dont know if a pinched nerve can cause "symptoms" so spread out..chest to shoulder to arm to finger? Is it a nerve or should i be concerned with something else? I have seen a neurologist who tested me for carpal tunnel on my left hand..(negative results) about 4 months ago. The chest "stinging" bothers me the most..and the numbness in my finger. What do you think it is?