It could be from dehydration. Are you drinking enough fluids? Burning sensations usually means your bones are lacking calcuim
I'm only 24 weeks and 4 days. I've been harassing the doctor and now there's so much pain in my pelvic area that I feel like it's breaking. I'm gonna have to just go to the hospital today.
I would start with a UA to see if you have an infection. My little guy is low and pushes up against my belly constaintly. It seems as if I always have a UTI. If your Dr doesn't want to help go to an ER and tell them you think you have a UTI or bladder infection they will check and then you can bring up your symptoms to see what they think. Hope everything gets better for you