We are on a Well and our water pressure decreases after only a couple of min, but then returns shortly after.

We are on a Well and our water pressure decreases after only a couple of min, but then returns shortly after.
More details please. Type of pump? Depth of well? Gage readings? Back to you. Tom

Could be a bad pressure tank. Do you know how old the tank is?

There is a small air valve at the top of the tank. Press the valve stem a few seconds. You should get only air. If water comes out, then the tank should be replaced. If you get only air, then turn off the power and drain pressure to zero by opening a low level faucet. With pressure at zero, add air at the top until you get a pressure reading (with a car tire gauge) of 2# BELOW the point at which the pump cuts on. So, for instance, if the pump cuts on at 40#, then you would set the pressure to 38#. Turn the power back on and see if the problem has been solved.