Irregular heartbeats are common and usually harmless. You're describing a preventricular contraction -- the skipped beat followed by the strong beat. This is probably the most common cardiac arrhythmia
. There are a LOT of PVC triggers (anxiety, lack of sleep, too much caffeine) and most of them are easily remedied. Only a few are related to heart disease
. You needn't see your doctor about it unless you begin to experience shortness of breath
, difficulty breathing
, dizziness and so forth.