What Causes A Prolonged Period After Child Birth?

hi im 18 years old and had a baby on the 17th june. i bled for maybe two weeks after having my baby then it was on off for bout 6 weeks i started taking the pill when my daughter was 8 weeks old as i fort i had a period but only figured out that ive just started my first period 3 weeks ago and still on my period now is that normal after having a baby?