It's not a big problem. In fact, a lot of chinese got TB positive including me. My doctor also suggested me to take the 9 month treatment. I accepted his advice. I have been taken the drug for 7 months.
It depends on you. Even you don't accept your doctor's advice, it's not a big problem. I have a friend, who is a nurse, she told me I could neglect totally the 9 month's treatment, since the drug is not good to your liver.
Anyway, positive TB is not a big problem. You can take the treatment or not. Good luck!!!!!