Heavy bleeding

I am 18 days post c section and my bleeding has been pretty light. I have been wearing a lighter pad lately. This morning around 5am I was nursing and felt some dull cramps, thought it was most likely my uterus contracting so after my son finished I popped an ibuprofen and went back to bed. i woke up a few hours later and felt really wet in my light pad and stood up and had a gush of dark red blood that pooled in the light pad. i went to the bathroom and again more blood came out, there were no clots just really heavy. after I cleaned myself up it went away. Is this normal? I don't have a fever and my incision looks great.