Hold the Sensor where the tail joins the main body. Aim toward the small of your back, and push it up. Once your Sensor is in place, you shouldn’t be able to feel it. If it's painful to sit down or walk around then the Sensor isn't far enough up the vagina. Insert your finger inside the vagina until you feel the Sensor. Push slightly, then do another walking test. The Sensor will never get stuck or lost inside you, there's nowhere for it to go.