I had to get an echocardiogram done recently for the military. because the meps doctor thought he heard a faint heart murmur. so my question is how worried should i be?. never had any heart issues ever?

Murmurs just means an extra sound, most often indicating a change in flow. Most "heart-bad" murmurs are found at birth or by 6 months indicating structural heart defects. If I listen to a patient often enough over the years I will eventually hear a murmur in most, at least transiently. During military exams they do extra testing to avoid recruiting people with possible health problems.