I have a 2 month old baby as i was playing with him i noticed a big lump on the side of his neck took him to the doctor she said it was calcium build. to me it didn't make any since to me?

Doubt Calcium: Could be a gland, muscle spasm or a growth. Why not get a second opinion from a good pediatrician or family practitioner?

Hematoma at delivery: Could be a hematoma as the result of delivery at birth. It should recede with time.

Neck muscle bruise : To deliver the shoulder (after the head is out) the neck is often stretched to the point that a bruise occurs in the stretched neck muscle.This often produces a bruise in the muscle & may form a transient calcium deposit from the blood pocket that forms.It usually dissolves over time but may produce a head tilt to one side while it is there.