oil flow

3800 engine... oil is pushed out of filter but is not replaced. believe that oil is not getting to oil pump.. need 2 no the odds on oil pick up failure. can oil pressure regulator cause such probs.. believe that if oil is pushed from filter then pump should b ok. need 2 no best way to chek oil pump. also need possible solutions. time is cri8tical.......

Put a mechanical gage on the oil pressure port near the oil filter housing.