Discuss with doc
If i listen to a kid often enough as they grow up i will eventually hear a murmur in most.
Mild systolic ejection murmurs are often just flow related, like the noise water makes in a babbling brook .Flow thru slightly narrow pulmonary arteries are frequent a cause of systolic murmurs. Clarify with your dr whether the murmur means anything. Most murmur"bad" is addressed at birth.