Primary
liver cancer is fairly unusual, and the presence of a
liver cancer usually causes no pain until it is quite progressed, so I believe with clear ultrasound and clear CT-Scan, you can exclude liver cancer as the cause of your pain. (Furthermore, unless you have a pre-existing liver disease such as cirrhosis, hepatitis, hemochromatosis, primary liver cancer would be highly unusual.)
I hope your pain and discomfort is resolved soon, and best wishes for a speedy recovery.