I received the S6 Edge on Wednesday and I've taken note that when the phone is in my shirt pocket, the heart rate sensor flashes. Playing around with it in my pocket it seems that when ever the shirt material gets close to the sensor it beams the red light. I've taken the phone of my pocket and the same thing happens if any object gets close to the sensor. Is this how it is suppose to work? I feel I may have a defective phone. Thanks and pardon if this is a dumb question.