Oil Pump

Dodge Intrepid, 2001, 113,000, V6, 2.7L

im a student traveling from Alpine tx to el paso tx thursday sept 13, I checked oil was missing some to added a quart, Friday 14, left to el paso on my way From Alpine to Marfa tx my oil light turns on, and car sounds like a diesel engine, I pull over to the side stop the car let it rest, noise goes away, travel another 20-30 miles and light turns back on, and engine gets the sound back to diesel engine.
i reach Valentine texas, from there to Van Horn tx, the light never turns on again.(That about 79 miles or less ) Stop at Van horn just to check everything, and head out to el paso. Again light never turn on. My question is what do you think the problem is? OIL PUMP? I use 10w30 OIl mechanics tell me to start using 10w40. One thing I left out was that on thursday the 13, I added alittle more oil than what I was suppose to, does that have something to do with the problem. Today is Saturday the 15 and the car has not acted up. Should I just get an oil change or should I just get the pump.

Please Help :)