Bulldog heat cycle

Question
My female Bulldog is in heat and I know that it is a 21 day cycle but what I don't know is, how long does she bleed for?  Is it 15 days?  

Answer
You may, or not, see bleeding for the entire cycle. Obviously the largest amount is in the beginning with bright red blood which will fade to a pinkish red in mid cycle. You may also see a darker, brownish red blood here and there toward the end of the cycle.