is it heart related?tiredness in my chest and skip a beat

for months ived been feeling tired in my chest...every morning....i felt chest pains to on my left breast....and sometimes at the back and i felt chills all over me....i do experience skip a beat too... ived seen my doc..and he said that im fine...i just lack physical activity... my ECG is fine...so are my xray....though my blood testing is fine...my lyphocytes is a little bit higher than normal....but my doc says its normal......what should i do??