Toward end of 30 minute jog, heart palpitated 3-4 times. i stopped and walked for additional 5 minutes. should i be concerned? (no other symptoms)

No, but curious.: Remember, your heart rate goes up while jogging, and you will feel this while jogging; that's obvious, of course. But if these 3-4 beats felt different than that, then I'd be curious, especially if it recurs. Do you have any medical conditions, heart-related or otherwise? If this recurs, you may want to run with an event recorder on, just to see what the heart's doing in that moment.