As parents gain more experience and the confidence that goes with it, they will find they need to call less. Most parents do not have medical training. Some problems seem very serious to the parent, but the pediatrician knows that there is nothing to worry about. On the other side of the coin, parents may not always know when something that seems trivial is really an important sign of a problem. Never underestimate your parental instincts.
Parents know their children best.
They often know that something is not right even before it is obvious to someone else. If you are concerned, your pediatrician needs to be concerned.