The pain may be sometimes associated with weakness in ligaments around the lumbar vertebrae due to pregnancy. That may sometimes cause irritation of the nerve roots and cause pain..
Next Steps
I will suggest you to start with hot fomentation, take analgesic with muscle relaxant tablet forebrain relief, take
calcium and
vitamin d supplement for strengthening the vertebral column.. You may use lumbosacral belt for support. If the pain is persistent, you may go for X ray of Lumbosacral spine or still better would be MRI of lumbar spine.. to rule out any other possibilities.
Health Tips
Avoid forward bending, avoid sitting down, avoid Indian toilet, avoid heavy work.