Dying Oil Pump???

It just happened today. When I looked at the oil pressure gauge today, it look like it’s losing pressure and back to normal again. the range is just +5/-5psi. Hope you know what I mena. In other words, if I keep rev at 2k rpm, I will see the needle of the oil pressure gauge keep bouncing +5/-5psi at whatever psi it is every few sec. I have an Autometer electric oil pressure gauge and the sensor is connected to the block with a nylon hose instead. I have had the gauge for more than a year. I checked underneth the car and found no oil leak. Anyone has exp? Is it my oil pump causing the problem or the nylon hose is a bit clogged?