Day 4 heart skipping and palpitation stress test came back good and im not dehydrated what could be wrong? no alcohol, caffeine or drugs. on monitor

Hard to say: You say you're on a monitor. I am assuming the results are not back yet. If the skip beats and palpitations occur while you are on the monitor then a record is made and your cardiologist should be able to get a better idea of what is going on. Many have ways for you to mark when you have symptoms, too. An electrophysiologist (heart rhythm specialist) should be able to help.