A fluid flow control apparatus used in medical fluid sampling. The apparatus includes a valve assembly, first and second ports, and a cap. The valve assembly comprises a body rotatably assembled to a housing and defining a passageway and at least two recesses defined by an interior surface of the housing and the body which is formed separate from the passageway. The ports extend from the housing and are configured for connection to medical devices. The valve assembly is operable to interchangeably align the passageway and the recesses with the ports. Finally, the cap is connected to the housing, and forms an opening for coupling to a specimen container.