Check the specs for your particular model and that you are using the correct oil for your application. Once warmed, you should get about 10psi 20psi or more at idle, and around 30psi or more at 3000 rpm. The loose in psi may be a sign of pump or engine wear, but losing a bit of pressure shouldn't be of concerned. If necessary, you can double-check with an oil pressure gauge and compare. Sometimes, if the oil pump is damaged, the computer will go into limp mode and you'll see a lack of performance, but your pump may be working okay. You may want to double-check for pending trouble codes, even if the engine light is not coming on, just in case.
This other post may help as well: