What could be wong if you have pain on the back left side near the bottom of ribs and it has progressed to occasional neck spinal pain constant chest tightness nothing abnormal in back or chest xray?

You might have pulled your muscle. One of your lats runsfrom your waste up to your shoulder and then connects with your neck muscle. Try stretching or go have a deep muscle massage. Or try taking a HOT bath with a lavander, chamomile bath salt. (Found at walgreens). Repeat any of these as needed until pain subsides. This may be from a strained intercostal muscle (muscle between your ribs) or a rib that is out of place. If when you take a deep breath an you are getting rib pain. This is likely from an out of place rib. Have your MD send you to PT after getting your cardiac status cleared.