I started to feel 1 or 2 skipped beats while exercise. Had 24h holter, Echo and treadmill test 3 years ago. Nothing abnormal. Do I need to test again?

Probably not. Of course it would be best to evaluate your heart again but the previously normal testing (I presume for the same reasons) makes a threatening condition less likely. What I would do is revisit the physician that originally evaluated you and inform him of your symptoms.