I have ben on the pill for almost a month now and recently I had discovered I had b.v (bacteria vaginosis) so I had ben taking flagyl (the generic pill form) I ended my flagyl pills yesterday and today half way threw the day I see a lot of thick dark brown almost black disharge with stringy like membrane in my underwear after I missed a period last month (April) there's no smell and it honestly looks a lot like poop! Can you tell me what's wrong?