My stomach is burning and very tender after my car wreck last night. Why?

I was involved in a car wreck last night. A vehicle pulled out in front of us and we hit them going 55 mph. I was holding my chin when I got out. I was hit in the face by the airbag and have a lot of jaw pain. My main injury was my stomach was hurting. Cramping and burning. I was rushed to a hospital via ambulance. Their ct scan was down so they did an ultrasound on my organs but didn't see any internal bleeding. (The dr didn't seem very confident) After exrays I was released with just internal bruising. Its been 24 hrs and my stomach is very sore and still burning. Is this a sign of anything or is this a normal feeling? I'm very tender on my right pelvic area also. I'm debating on going to our local hospital and ask for a ct scan. "Oh, and yes I was wearing a seatbelt.". Any helpf advice would be appreciated.