Dark/bloody discharge question

Before my last two periods I've experienced break through bleeding about a week before my period comes. I haven't goofed my pill up at this month either. To me it doesn't look like blood but very dark almost black mucus. I need to use a panty liner but after urinating when I wipe there is clearly blood and I usually see clot(s) in the toilet. It's also causing my labia minora to feel irritated and itchy (which might be from the panty liner).