Bleeding after a miscarrige & d&c

I lost my son April 13th bleed on and off with spotting until may 1st. Then on the 13th I started passing clots and spotting, yesterday and today I have had heavy bleeding and really bad cramps unbearable. Is this something to be alarmed about? Is this my first period? Or is this still from losing my son? I was 16 weeks when I lost him. Maybe it would be best to ask a doctor but sometimes others who have been threw it can explain it better then a doctor. Thanks