Abnormal mammograms are more frequent with the new digital technology. I would guess this is totally unrelated to your melanoma of 7 years ago that was low risk. I went through a similar scenario and did have a biopsy that showed fibrocystic issue, not cancer. Being on the same side as the melanoma is not consequential. If you don’t trust the provider, get another opinion on waiting. But I would try not to worry, since it is highly doubtful to be related to your melanoma. Another opinion may relieve your worry. Or talking further with the doctor. Let us know how things go.