Blood work, chest xray, ekg done and everything came back good. i still have a pain in my right chest when i breathe. what can it be?

pleurisy: It can still be either pleurisy or muscular pain (of the intercostal muscles). In either case, a non-steroidal anti-inflammatory drug such as Ibuprofen or Naproxen is likely to provide relief.

Musculoskeletal : If the pain is reproduced with pressure over the area or deep breathing it may be related to the breathing/chest muscles or rib movement with breathing. Other possibilities include pleurisy or other pleural diseases , atypical heart pains, blood vessel problems. You will need to follow-up with your doctor.