Hi, I Am Karthick Raja From Chennai, Before 15 Years

hi, i am karthick raja from chennai, before 15 years a dog was bite my right buttock i weared two clotheson that time the outer cloth is teared and inner cloth is not teared but a drop of blood came i washed well but no treatments taken,now i am panic on it, shall i get rabies injection now. what are the possibilities to save my life at present.Please reply me as soon as possible.