I was sledding with the kids and hit my ribs against a tree. i went for x-ray and they were negative , but now under my left breast their is a bump?

? bruise: If the bump appeared within 1 day of sledding then likely it is a "hematoma" a collection of blood near the surface, like a bruise. However, if it appeared later than that i would be concerned that you need to have it evaluated for cyst or breast cancer. If the bump is not resolved in 2 wks or less you need md to evaluate. Remember men as well as women can get breast cancer so dont ignore it.