Chest pain on random days. To me?.

Since from 2015 ., Am Suffering from cough ,chest pain and digestion problems. I consulted a doctor in 2016 and I told him about the problem am suffering, he told to go through set of tests like ECG, BLOOD TEST etc..and finally he said that, it's because of gastric and gave medicines, .. After few months, again in 2017april., I stated suffering from same problem, and went to another doctor this time, he said to go through chest X-ray, and the reports were normal, so doctor said"nothing is happened to u" .. again after few months, in December 2017,am suffering from cough and that too with blood from 2 to 3 weeks ...I get reddish cough in early morning on random days , and little chest pain .. So may I know what actually happened to me?.plz