Hello and welcome to HCM,
There are many causes of ec=xcessive bleeding during periods.
The most common causes are hyperplasia
of endometrium and cancer of the endometrium, etc.
The most appropriate investigation would be endometrial curreting or endometrial biopsy
If your doctor suspects TB, it should be confirmed by stain for TB bacteria and/ or culture for TB.
TB gold is not a very sensitive and specific test for TB.
It is even banned by the govt of India due to erratic results it give.
Positive TB gold does not imply presence of TB and negative TB gold does not imply absence of TB.
I hope my answer helps you.
Thanks and take care.
Dr Shailja P Wahal