guy,
thanks for the post.
Im assuming you havent been looked at by a health professional. The only way to diagnose a heart attack is to be examined, have an
ECGEcg
Electrocardiogram (ecg)
Exercise stress test
Post myocardial infarction ecg wave tracings and some lab test. If you have concerns about your chest pains you should be examined.
Your exercise didnt bring on a heart attack and I would argue if you had an event, it probably is why you havent had one before now.
Get evaluated. No matter what, fitness will be an important component of your future cardiovascular regimen.
good luck