What Causes Severe Pain On Right Side Of Abdomen Radiating Towards Back?

Hello, I am 41 year old female. I have been having a pain in my upper right abdomen, sometimes it feels like pulling. I have a hard time lying on my right side in bed, and I've had some problems while sitting. It almost feels like it is swollen or something is there. I always thought it was probably a hernia from the long labor I endured with my only daughter. The other night I went to sit down at the computer and a severe pain started in the right abdomen and radiated to the back. I lost my breath and it almost reminded me of labor. I headed into the emergency room but then it quit about 25 minutes later. What do you think it could be?