It may be normal physiology to get low backache and pelvic pain during 3rd Trimester. This is due to loosening of sacroiliac Joint and pubic symphysis.
Next Steps
Keep hot fomentation.
Do urine test to rule out urinary tract infection.
Make sure u r taking good amount of
calcium and
vitamin D.
Health Tips
Do exercise that are allowed during pregnancy.
For further evaluation and management, take online consultation.