I had something like this during my first pregnancy. My doctor said that although my ribs hurt, it comes from my thoracic spine. Not much I could do about it (other than my other doctor offering me a shot, which I reclined). I found that a good balance between walking, sitting, and laying down helped a bit - plus back rubs from my husband
I have the same rib pain. Sitting doesn't help but doing some yoga stretches and lying down did help for me. I also got a prenatal massage this past weekend and she worked out some knots in my back which helped relieve the pain and pressure. The more you can stretch for a minute throughout day, the better it will feel. I feel your pain though, no fun at all. A heating pad at night helps too! Good luck!
I had this toward the end of my last pregnancy, turned out to be a rib out of place, which is common in pregnancy. I saw a chiropractor who helped a bit but it didn't really get better until after delivery when it just sort of went back into place!
Re: right rib hurts when walking