Pain in left breast, shoulder, back and arm

I'm 42 years old & never been pregnant.Been having off/on pain in both breasts but 80% in left breast for about year and a half. Pain started late 2007.  I took a mammogram in Feb 2008 and came out clear. Pain subsided for a few months and surfaced again about October 2008. I have taken series of mammo scans which also were judged normal. About this time, I started having premenopausal symptoms, hot flashes, break out in sweat suddenly, headaches, and the breast pain.
I took another mammogram Feb2009.It came out normal again but the hospital advised that I take a diagnostic mammogram because of the pain. My doctor felt exposure to radiation could be an issue. While debating what to do, I felt a mass in the left breast ( my breasts have always been lumpy and the left significantly different in size and shape) The mass was confirmed by several clinical examinations and one doctor advised a biopsy but a mammo scan to guide the biopsy didnt show any mass. I saw a breast specialist in London who felt a mass and ordered a scan by the consultant radiologist. They both determined that there was nothing abnormal  and such could not advice a biopsy but placed me on Starflower Oil to help with hormone imbalance. I havent had a period since Mar 2009.

The pain is not going away.It feels hot sometimes, sharp deep in my chest area through my left breast especially. There is no physical change in shape, skin, nipple though sometimes, i feel like itching both breasts.The pain spreads to my shoulder, shoulder blades, arms and back. 3 weeks ago, my left shoulder started to hurt if I move it randomly, the pain snaps my hand back.

I dont know what to do anymore. Should I have additional tests? will an MRI be better than a diagnostic mammogram? Are the doctors missing something? I heard of women who only felt pain in their back and discovered they had breast cancer. I feel something is going on inside my left chest area I took a chest xray and it was normal.pls help

[Cleveland Clinic]

Dear Purrples, Over the internet without ability to evaluate including scans and physical examination it is impossible to advise specifically regarding your symptoms or recommend what to do next.  If you do not have a breast specialist perhaps this might be the route to go - a second opinion with one who could evaluate your case.  These specialists are usually associated with large acedemic centers.