I had a heart attack out of the blue myself, thinking I was in fair health. As far as I know there is no heart disease in my family either. My attack felt like a few slight pains that went away on the left side also that's why I dismissed it. Then one day I was having a meeting online and it felt like a rubber band was squeezing my torso. The pain was not unbearable but it became constant. I ended up in emergency surgery due to a heart attack. After talking to my doctors and doing research I found out that many people don't have any symptoms at all before a heart attack. I don't know what's going on in your case, but I would definitely keep an eye on it and if that little pain starts happening more often or becomes even a little bit stronger I would go back to the doctor ASAP. Because I waited instead of going to the ER right away I ended up with alot of damage to my heart.