extra heart beats- not usually a problem
extra heart beats on ECG sometimes called ectopics are of no clinical significance as long as the shape of the heart beat is normal on the ECG.
Anyone can get them and lack of sleep, caffeine and any stimulant drink can produce them ( So can Brandy but of course pilots don't drink!!!) . So get your ECG when you are rested and minimal caffeine and I cannot see a problem.