Can a pinched nerve from the spine go down the waist and leg?

For about 2 months now I have been having pain on the right side by the waist area and back. It started off on the right side by the waist and the back and then now it is on my right leg. I did 2 abdominal cat scans. One showed liver enlgarged and the other (done with contrast) showed normal. At first one of the liver enzymes were slightly elevated but then a couple of weeks later they were not. However the sonogram showed liver enlarged. A few doctors said that the pain can be from a pinched nerve from the back but the MRI showed normal. Can it still be a pinched nerve from th spine even the the MRI was normal? I went to a neurologist and they said I should do an EMG to find out if it is a nerve pain or not. They also said that it can be from the epidural I took when I was in labor for my 4 months old son. The GI said that the enlarged liver can be from the pregnancy. Is this true? I am confused about all this. IF anyone has any suggestions let me know. Thanks.