period after birth

Ok I had my daughter back in June, and I Breast feed, therefore I haven't had a period besides spotting here and there. The other day I started what seems like spotting only to wake up in a full blown period. Is it normal to have very heavy bleeding after having a baby? It's so heavy I can't wear anything due to the faceted I bleed through everything, pads aren't really working out either unless I change them often.