I have soreness on my left breast and went to a doctor yesterday and at first he said he thought he felt firmness and then he saw a bruise.

Needs Further Tests: IF you have a "new" breast tenderness and your doctor "felt" something, you should have further testing. This would likely include a mammogram and possibly breast ultrasound. If there was a trauma to the breast, it could leave a bruise and cause some firmness in the deeper tissues. Although that can be normal, I would recommend follow-up.