the past four nights I have woken up with tightness right in the center of my chest. it dissipates out towards the right and left sides of my chest a little bit (probably until about mid what in each rib cage). it isn't like a pain, but more of a tight and short of breath feeling.
i have also had a fluttering feeling in my heart about 3x in the past two weeks. i find it odd because i haven't never experienced it before. it lasts for about 3 minutes and then it goes away .

i am a F 19 years old 5'5 and 116 pounds. i am very active , run about 30 miles a week and eat extremely health, no fried foods, lots of salad and vegetables and small amounts of meat. . i am also not a smoker .