what are the signs of improvement in sputum -ve Tb patients

dear doctor, i have been on anti tb drugs INH,PZM,RIFAMPICIN,OFLOXACIN,ETHIONAMIDE since 5 months and INJ STREPTOMICIN since 2 months now..i had been my sputum for AFB and CULTURE negative since the start only POSITIVE findings were my xray and mantoux..now on review some doctors say its the wrong regime and now i just can continue it for 4 more months and do a repeat xray to check for improvement...MY QUESTION IS how am i supposed to know i am on the right treatment and am i improving or not?? at present i have not gained weight after i had lost 6 kgs initially but my diet has really improved , i jst have slight chest pain at times but no fever or cough...PLS HELP