What Causes Abnormal Vaginal Discharge After Delivery?

Hi I m mother for two children, they are 18months and 7 months. Last 3 months of person cycle is 25/26 days. Having little too heavy bleeding and last 2days and normal bleeding and discharges stayed upto 7/8/9days. After 14/15 days of period I m getting a brown bulky (jelly type clear with brown) discharge last few months. It happens on 13/14th day. When that comes I have very uncomfortable feeling on abdominal area feeling heavy as well. Is there any reason I m getting discharge like this? Thank you