Thanks for writing to us at DoctorSpring.com with your health concern.
The reddish discharge and the history of trauma to the breast suggest a breast haematoma / traumatic fat necrosis.
This is due to injury to the breast tissue , leading to collection of blood inside.
I would advise you to immediately see your doctor and get examined.
Warm compresses / antibiotics / tight bandaging maybe required.
It is less likely to be cancer. But cancer can be ruled out by clinical examination in conjunction with an ultrasound / mammogram.
All the best
Please feel free to discuss any further queries.