I have some swelling in my right pectoral. I did some chest, arm and shoulder work about 3 days ago and noticed this morning that my right upper chest has swollen to about 15 - 20% larger than the left. There's no major pain or discomfort but I am concerned I've done damage. Any advice?
Unless there's pain, you've probably caused some mild damage to your muscle. Rest for a few days and see how it progresses. If it gets worse - see a doctor.