Given below is a commonest method to track your heart beat,without using any instrument.-
Try finding your radial pulse, if you are having difficulty finding your carotid pulse. This is found by taking your forefinger and middle finger of your right hand and placing them horizontally across your wrist, once inch below the bottom of your hand. This is a very common place to measure heart rate from.
Count the number of pulse beats you feel in thirty seconds. Remember that counting pulse beats is the same as counting heart beats.
Multiply the number of pulse beats by two to get your heart rate. Heart rate is generally measured in beats per minute.