I Have Pain Under My Right Breast And Goes Into

I have pain under my right breast and goes into my back between my shoulder blade and the same spot on my back where the pain under my breast is? I have no gallbladder so this can't be a gallbladder attack. I visited my doctor and he diagnosed AC shoulder separation and prescribed anti-inflamatories and a sling for my arm. While my shoulder is tender to touch in that joint, doesn't it usually take a hard bump or fall for something like this to happen? Surely this doesn't account for the ACUTE pain I still have that I refer to above. Please help. Thanks, Claerwen

Source: HealthTap, https://www.healthtap.com/user_questions/0000