I know a good massage helps my back. So if you have someone who will rub it or the finances to afford going to get a proffesional prenatal massage you'll love it. Also if you're able to go to a chiropractor. I've never been since preggo but I've heard they can really help when the pain gets unbareable its just expensive if you don't have insurance coverage.
They also say doing exercises to help strengthen the back and abdomen really help too.
Good luck
Well my boobs are bigger but not my belly.....I have puy eater bottles in my back to relieve the pain.
The extra weight of growing belly and boobs can pull your shoulders forward and cause the back pain. Try sitting in a straight back chair with your back against the chair a few times a day. This helps me. Hope you feel better. It's not fun when you're already dealing with so much and pregnancy throws another curve ball. :(