Hello, I went through your query, we always expose to tubercular bacteria either knowingly or unknowingly, it's our immune system which prevents us to getting disease from the bacteria. In TB patients if bacteria is responsive to antibiotics, sputum will be negative with in 2months,, don't worry, keep your self healthy active, by eating healthy diet and daily exercise, avoid smoking and drinking. If you get cough, night sweats, evening rise of temperature, loss of appetite, weight loss, Consult physician..