Could you have pancreatitis for many months with only a very mild discomfort in ruq area and absolutely no other symptoms or would it get progressively worse over time and cause significant pain?

RUQ pain is more consistent with Gall Bladder problems or even stomach ulcers especially in your age group. Talk to your regular Dr for a thorough evaluation which may include labs and imaging. Prompt treatment of either of these will prevent progression to worsening disease that may eventually require surgical intervention. Pancreatitis pain is typically more central and may radiate to the back.