Many children get apprehensive at the doctor's office, for a variety of reasons.
Infants from roughly seven to 10 months old are subject to stranger anxiety. They cry when strangers approach or when they lose sight of their parents amongst strangers. Toddlers and older children may remember past unpleasant experiences at their doctor's office. If those experiences were intense enough, some even cry and scream upon pulling into the office driveway. These are normal developmental reactions and tend to resolve as the child matures.