Blood comes from mouth. Start diagnosis?

Monday morning (24 december) , blood came from mouth while coughing. it is red coloured and coughed six to seven times in total ,total quantity will be half of spoon approximately. i know that blood doesn't come from mouth gam. when i searched on internet and find out that blood from mouth is very alarming, may result in very serious problem(even in cancer) My wife generally drinks water less than normal. Please guide which doctor i need to go , from where i can start diagnosis?( Doctor type , name and hospital near noida stadium) Any help will be appropriated. Thanks in advance. Patient details: 29 Year Female , have stone width 5mm in lower pole of right kidney, taking medicine (Topaz 75mg,Amitone 25mg, Headset on sos) for treatment for headache from past 3 year(march 2016) continuesly by neurologist.