A flow control apparatus adapted to load a feeding set having an upstream side and a downstream side including a housing capable of receiving at least a portion of the feeding set. A pumping device contacts the feeding set when the feeding set is received by the housing so the pumping device acts on the feeding set to produce fluid flow in the feeding set for delivery of fluid to a subject. An ultrasonic sensor is arranged with respect to the pumping device to detect a change in pressure in the downstream side of the feeding set when the feeding set is loaded on the apparatus.