Systems and methods for determining the position of a fluid within a fluid source and infusion line coupled to an infusion flow control device are described herein. An exemplary system and method includes sampling fluid pressure upstream of an infusion pump, and calculating fluid pressure slope profiles. By sampling fluid pressure upstream of an infusion pump at discrete intervals and monitoring fluid pressure slope profiles, conditions of fluid flow, including unintentional fluid flow through an infusion line or a defective check valve in an infusion line, are detected, and fluid flow through an infusion pump is controlled.
