1990 Chrysler Le Baron Oil Pressure Gauge

My 90 Lebaron is running fine except for an oil drip. But recently when I am driving and come to a stop the oil pressure gauge drops to zero but as soon as I give it gas it goes right back to normal.

As I said it is running fine and even when the guage drops the engine sounds ok and there seems to be no problems.

I had one person say its the oil pump and another say it must be something wrong with the gauge.

My concern is should I stop driving it or can I keep going and wait before having it checked. As you can see by the cars age I do not have the money for expensive repairs.

Thank you