help!

I have pain on my right rib cage under my breast inflamed. The pain come and go to my right side back. The more kids I have the intense the pain. Always happen around 5 months up. Right now I'm already 7 months and the pain is unbearable. I can't sleep or walk or sit for a long time. It's like a burning sensation. My last pregnancy my dr did some blood work for gallbladder and came back normal. I was scheduled another ultrasound to see what's causing the pain but had my baby. Now is happening again with this baby. If the pain come and I try pressing down where the pain is feel like it's going to explode.  Anyone experiencing this before? I need help! Spoke to my dr and she said if I can't no longer take the pain anymore go to labor and delivery room. Any suggestions?