well pump kicking on and off every few minutes
There's a leak, assuming the pressure is varying and the pressure switch is operating normally. 

If you are not seeing a leak, the most likely one is in the check valve at the bottom of the well (though we don't have any information about the type of pump you have - on a submersible pump, that check valve is in the top of the pump itself.) 

You might also have a leak in the pipe between the well and the house, or in the well itself. 

Finally, you may be running water in the house without being aware that you are - water softeners with faulty valves have done this to me, and leaky toilets are another common cause. If you have a main shutoff valve after the pressure tank, you can shut that off for 10-30 minutes or so and see if the pump still runs every 5-10 minutes or not. If so, look to the well side - if not, look in/around the house.