Only a suggestion but could the symptoms be caused by gall stones? Sorry didn't occur to me this afternoon when I read thread but just had a though now so logged back in.

When I had my scan last week (32 weeks) a gall stone showed up on the u/s. Now I haven't had any pain or anything but did usual "google search" when I came home. Apparently they can occur during pregnancy as like a lot of things inside the gall bladder doesn't operate as efficiently as it normally does which leads to deposits of calcium and something else building up which turn into stones. When the gall bladder is producing bile (I think) to help digest food it contracts which if there are stones squeezes the stones which cause the pain. (At least this is what I've read).

I'd ask your doctor to make sure your scan was taken by a machine that would also have been able to pick up if there was a stone in the gall bladder (and maybe bile duct). My stone has only shown up at 32 week scan nothing showed at 7, 12 or 20 week scans. All mine were done at property Ultra Sound clinic where the machines are a lot more powerful that those in doctors or OBs. If not get them to do another u/s - obdominal one this time so they can at least eliminate.

Hope this helps but doesn't just give you something else to worry about.

Keep us posted on how you go.