A vascular access port system including circuits for detecting and indicating the presence or absence of a needle. The detecting and indicating circuits may be carried in whole or in part by one of or both of the needle and/or the vascular access port. The detecting and indicating circuits may utilize a conductive needle, a mechanical switch, a magnetic switch, a Hall effect sensor, an electric field, a magnetic field, or an inductor, for example, for detection purposes. The vascular access port system permits the practitioner to confirm that the needle has been correctly inserted into the VAP, and notifies the patient and/or practitioner if the needle has been accidentally withdrawn.