Thanks for your question on Health Care Magic.
I can understand your concern.
In my opinion, you are mostly having
endoscopy related pain.
EGD (esophagogastriduodenoscopy) is an invasive procedure.
And minute internal trauma is likely to happen.
This trauma can cause post procedure pain in center or left side of chest.
So no need to worry much for this pain.
It will resolve by its own with time.
Your shoulder and
neck pain is mostly due to bad sleeping posture.
So you can apply warm water pad on affected areas.
Don't worry, you will be alright.
Hope I have solved your query.
Wish you good health. Thanks.