Having intense upper & mid abdominal pain on both sides that goes through to back. US says, trace amount of intrapelvic fluid, what could that mean?

REALLY cannot say. Without an actual examination, I cannot give specific medical advice on your particular health situation. trace amount of fluid is normal. and.... aortic aneurysm (very unlikely) pancreatitis appendix pelvic inflammatory disease many many other very nasty potentially rapidly fatal diseases cause abdominal pain.