What Causes Stains Of Blood In Sputum?

Hi! I m neha 2yr ago I had developed a swollen mass on the rt side of neck.i had taken homeopathy medicine .after 5month of t/t pus came out but the wound is not healed.then I had taken antitubercular drug for 6month ,den all gets normal.today morning after coughing I saw expectorent is tinged with blood stains .what should I do?i m 23 yr old