Early signs of Breast cancer

Hello, 

I have recently noticed a white indented circle on one of my breasts, I contacted my doctor who didn’t seem to know what it was an referred me to the breast clinic. I had an ultra sound and the consultant was happy they is nothing attached underneath the skin to this circle and seem to think it’s a skin pigmentation. But I’ve also been experiencing some dull pains/swelling in and around my armpit on the same side and can’t help but feel like there’s more to this but not quite sure what to do next? 

Many help/advise would be gratefully appreciated.