Your pain might be caused by either stomach ulcer
, gall stones or intercostal neuralgia
(what is most probable). However it is always advisable to rule out heart attack
or ischeamic heart disease
when pain in chest appears.
You should have an abdomen ultrasound (what should rule gall stones out), gastroduodenoscopy (to rule peptic ulcer out), some blood tests including pancreas and liver enzymes, magnesium and calcium level (shortage of this ions may result with some nerves irritation including intercostal nerves) an at least ECG to rule out heart problems.
Hope this will help