I have a brownish cloudy discharge at the end of my period?

I get a heavy period for only 3 days and lately it seems to start off with dark brown blood then turn bright dark red and heavy and now a couple days after its over its dragging on with "episodes of brownish (old blood) and cloudy like discharge ! I seem to always have to wear a liner? Any advice never seem to happen before its like there’s a backup or a slight blockage? I’m not on the pill or anything bec we would like to get pregnant with Baby #3 soon! Never had problems with irregular periods been under some stress lately only been day or two late (Avg cycle is 29-30 days!) but just unsure of things wanted to see what everyone thought! Need to make an appointment but.......