The doctor said that my child has an "innocent murmur, " is there any chance that this is an asd?

Yes: Most commonly an ASD can be distinguished from an innocent murmur by listening alone. There are rare exceptions.

Depends: The ASD is often diagnosed clinically by a fixed splitting of heart sounds rather than a murmur. Most of what are lumped into the term innocent murmurs are not caused by any structural heart problem. The most common has a twanging string noise like a base fiddle, but there are others.If the issue bothers you a echocardiogram could confirm the dx.

Possible but...: An innocent murmur is by definition "innocent". But we (doctor's) are human and mistakes can be made. However, diagnosing an ASD in a child is generally not an emergency. Many, many children have innocent murmurs. Though a significant ASD may sound "innocent" early in age, the murmur and other heart sounds will change over time. If your pediatrician remains concerned then you can be referred.

Asd: If he did an echocardiogram no there is no chance, if he only listened there's a very small chance a cardiologist may miss a small ASD