Post partum menstrual cycles are irregular. Is this normal? (TMI)?

Six weeks after my daughter was born, I started taking Micronor. I started my first period 2 1/2 weeks into taking it. Then, after that 1 cycle I switched to Yasmin because I stopped nursing. I got my period last friday, which was the first day of the 3rd week, lasted until Wednesday then I started again today really heavy. I am ping blood clots larger than a quarter. Sorry, TMI. Is this something I should be concerned about or is it normal after having a baby? Also, cramps are worse than prepregnancy.