Hello Good Evening,
A ECG is just a screening test for cardiac problem, and it can give false positive and false negative results.
Though you had a fine ECG, but if you have symptoms, then you can go for TMT and Echocardiogram
of the heart.
You had mild fever
, so you can also have possibility of your pain originated from respiratory tract
or musculo-skeletal system
So you should go through proper evaluation with proper clinical examination and following investigations:
Further management will depend on final diagnosis.
Dr. Naresh Jain.