Inverted T Waves On Ekg. I'm A 21 Year Old

Inverted t waves on ekg.

I'm a 21 year old female and I recently got a ekg done due to heart palpitations. It came back with inverted t waves over the anteroseptal leads. I had a echo done, everything was normal. Also had a chest mri and blood work. Everything was normal. My doc compared my recent ekg to one from a year ago and it was similar with the inverted t waves. What can this be?

My doc said not to worry that it can just be normal. I don't have chest pain. And everything else seems to be normal besides these inverted t waves. I have a stress test coming up just to rule out everything.