Hi! I've Had A Chronic, Dull Soreness In My Left-chest

Question: Hi! I've had a chronic, dull soreness in my left-chest area. The pain can be felt behind my left shoulder blade, but does not go lower than my diaphragm. It doesn't appear to be a muscle pain, as stretches targeting the affected muscle area neither help nor alleviate the pain. The pain is not affected by breathing, eating/digestion, sleeping/waking, or physical activity. I do not have a fever, sweats, confusion, or any changes in appetite or temperament. I breathe normally without struggle. The pain does not stunt any day-to-day activities and does not appear to be triggered by anything. It's been a constant in my life for the past few years - much like a persistent back ache. However, given the location of the pain, I am concerned as to whether or not internal organs are at risk. Internet symptom checkers have so far stated that I should panic and go to the ER. However, due to covid, I am apprehensive of the notion. My resting and active heart rate is within the healthy range for a man my age (31), averaging around 85bpm at rest, and 95ish during my exercises. I am a bit overweight, do light exercise 3-5 times a week, and am a non-smoker. The pain seems to be the only symptom. Should I be concerned? I understand that I only have one symptom to go off of, but does this sound like any serious medical condition? Or something that can be treated at home? Thank you.