A murmur is caused by a disturbed blood flow which is almost always a result from a leaky heart valve.
Leaky heart valves are very common.
There are several grades of leakage. As long as the leakage is mild, there is no reason for alarm. When the leakage is moderate, monitoring (once a year) is common practice. When the leakage is severe, more frequent monitoring may be needed and also a restriction in physical exercise may be necessary.
Not taking proper action in case of severe leakage may lead to heart failure.
This monitoring is done with an echocardiogram.
To find out how serious the murmur in your case is, needs to be investigated.
So yes, you should take the test.
You need to get it checked. Echos are cheap, a very sound investment in your future. Most likely nothing to worry about but why chance it?