In other words, when you are distracted and active you do not get shortness of breath or chest pain. This is inappropriate and speaks against any underlying disease, as does your inappropriate awareness of your heart beat. Stabbing transitory chest pains usually come from chest nerves and are of no significance.
Your asthma undoubtedly makes you aware of your breathing and heart function, but what you describe is not the normal occurrence.
You may need some psychologic counseling, but I suggest you first check in with your family physician to clarify the status of your bronchial asthma.