1995 Ford Probe Car Engine Oil Pressure Question

Engine Performance problem
1995 Ford Probe 4 cyl Automatic 147000 miles

I was driving on the highway for about 25 miles. I exited and stopped at a traffic light. As I came to a stop, I noticed that my oil gauge dropped to L and then rose back to Normal, where it remained. I drove to the next stop sign and came to a halt and the oil gauge dropped to L again, then rose back to Normal. When I reached my destination I turned my car off and proceeded to check the engine oil level. It had a perfect reading. I've only noticed this today and I'm not sure if this is normal or if something is wrong. What are your thoughts? Do I need a mechanic and if so, could you recommend any? Thanks!