Nagging pain in left breast, swollen area by collar bone also doctor felt a lump. does this sound like breast cancer?

Possibly: It's possible this is breast cancer, but it could also be other things such as a local infection with swollen lymph nodes. Your doctor will guide you through the next steps, which may include a biopsy if there is a lump that he or she felt. Don't worry yet. You need to know the diagnosis first!

Not enough info: Pain in the breast, swelling, and a mass are not definitive for cancer. You need further evaluation - mammogram, possibly an US, possibly a biopsy. Continue your workup in order to find out.