It is highly probable the EKG is false positive . There is a segment of the heart cycle that is recorded on the EKG. The report would show an elevation or depression of the ST segment. There can be many benign causes for that configuration. An EKG requires further testing and symptoms to make a diagnosis.
Yes, it is possible to have had a silent heart attack. Symptoms would be shortness of breath, chest pains, etc. These symptoms would be the result of a low cardiac output caused by impaired and damaged heart walls because of the heart attack. I had a silent heart attack about 7 years ago. You shouldn't be overly concerned about the results of an EKG.
Thanks for sharing your experience, and if you have any followup questions, you are welcome to ask. Take care.