What Causes Heavy Vaginal Bleeding With Bad Odour Post C Section Surgery?

I am 26 years old and I have four babies, the most recent one is one month old today. My problem is that I am having a heavy discharge that is causing blisters in my pelvic area and a heavy discharge that smells like rotten eggs. It seems to really come out when I stand. I had a C-section each pregnancy. Should I be concerned?