The clicking sound is the mechanical valve closing - metal hitting metal. In some people, you can hear the clicking without a stethoscope. If the clicking stopped momentarily, and then you heard double clicking, you might have went into an arrhythmia. During arrhythmias, you heard beats so fast that the mechanical valve does not have time to close, and therefore, you wont hear the clicking temporarily. Arrhythmias are commonly caused by coronary artery disease, hypertension, electrolyte abnormalities, valvular heart disease, congestive heart failure, and heart surgery, as well as thyroid disease, endocrine diseases, illnesses, and kidney failure. You will need to get routine screening blood work to check your electrolytes, as well as an EKG. If you missed any of your medications, this could also be contributing. I would recommend getting seen by your cardiologist. You might need medication adjustment.