I Have RUQ Pain, Sometimes It Comes After Eating And

I have RUQ pain, sometimes it comes after eating and then it is sharp and lasts for several hours , sometimes it is just comes whenever and is dull lasting for 2-3 days. Blood work - LFTs normal, pancreatic enzymes normal, WBC normal. First US gallbladder negative, second US showed thickened gallbladder wall questionable acalculous cholecystitis, HIDA negative. Is is possible to have acalculous cholecystitis with all labs and HIDA negative?