I am a 24 years old female, very thin and weak gone through TB gold test but report was negative. Its been an year and we are unable to find which part of my body have TB. But I started TB medication course and gained 2 kg weight (now 39 kg) within 10 days of medication. On the other side I have pain in my tailbone since 7-8 months. I can't sit properly especially on hard surface. Now Doctor said it could be TB in my tailbone. Please suggest how to detect if I have that. We already spent lots of money on treatment and diagnosis, can't afford more. Kindly recommend appropriate test to detect TB in my tailbone or any other test to detect TB in any part of my body.