The bruise and pain at the left breast area may be due to the rib injury
and should be investigated.You should have the x-ray of the chest done and physical examination done by doctor.
The ct scan
may be needed in some cases to confirm the findings.
The rib fracture
if found should be treated with strapping in 8 shape after consulting orthopaedic doctor.
The pain can be controlled by drugs like motrin, advil, etc along with local application of the analgesic