Not all vehicles with oil gauges are actual gauges, some are really just glorified idiot lights with needles. Sounds like you have an actual gauge which is good.
I doubt you have an actual problem and replacing the oil pump was probably not necessary. I did read about a filter in the engine for the sending unit on this thread: https://www.cargurus.com/Cars/Discus...33921_ds539247
. Worth checking out.
I'd get your oil analyzed. There are kits available like this: AMSOIL OAI Oil Sample Value Kit
. This will tell you a lot about your engine wear by the metals dissolved in the oil, high levels of tin or non-ferrous metals can point to worn bearings.
Oil grade is also a factor, what weight are you using? A step up, as long as ambient temps permit, can help.