I know the liver does not feel pain. I know I have seen a number of posts on this site from people saying they felt pain in that area. Definitely not the expert. Gallbladder could be it, always a good idea to talk to the doc. But I thought I would mention that I did have pain in my side where the liver is for a number of days on tx, off and on, think it was about 8 weeks into tx. On the last day, I realized it felt like compression. It went away after a while and has not been back. I had a lung collapse when I was young, it did not hurt when it collapsed but it did when it came back, doctor basically said internal things shifted after the collapse and were shifting back. Kind of wondered if maybe it was similar. Anyway, know this isn't that helpful but you are not alone.
Also, here is one of the prior posts on this. Uncledudeness had some interesting info.
http://www.medhelp.org/posts/Hepatitis-C/Liver-pain-during-tx/show/1621323