Hi there
There can be different reasons for shoulder pain like rotator cuff injury, shoulder impingement, sprain or strain, muscle pull etc. It would be better if you go to an orthopedic doctor and have a X-ray of your shoulder.
Next Steps
visit nearest orthopedic doctor or can go for physiotherapy treatment for pain management of your shoulder.
Health Tips
rest, avoid heavy lifting, use ice pack for 15-20 minutes three times in a day.