abnormal ecg - Inverted T waves

hi there, i am a 17 year old that had a panic attack a few months ago, quickly rushed to the hospital and after taking an ecg they told me i had an abnormal ecg. they didnt take it too seriously due to the fact im a healthy, active and young person. however i went to another hospital because i moved and at taht time (and still now for about a week) have left chest ache. it isnt a sharp pain, jus a dull ache but it does bother me, at times i have to stop what im doin to take in deep breathes but the pain has never woken me up. The doctors at the hospital hav taken my blood twice to check for clots/signs of heart attack,high blood pressure and all was ok, however they took my ECG about 4 times and showed i definitely had an abnormal inverted T waves and sometimes the other way round with some that were  large waves and some short.
i have just recently found out that my father had abnormal palpitations as well but has never bothered him i.e no pain or any other heart symptoms. i am soon going to get an echo to really see whats happening with my heart but i just wanted to find out what are the possibilities or reasons why im havin slight pain?
thanks  Xavier