I am almost 5 weeks postpartum after a normal, healthy delivery. I stopped bleeding about 4 days ago then last night I suddenly had some brown discharge that was tinged pinkish red. I was VERY disturbed to find a pretty large sized brown mass in my underwear. It was not a blood clot and did not really have an odor. It was kind of spongy. I am not sure whether this is normal or if I should call my doctor. What could this be?