Why does my discharge smell like butter? also it looks kind of white and chunky in my underwear. not an std, i got tested, came back negative.

Maybe yeast?: A yeast "infection" isn't a real infection, STD or otherwise, just an over-growth of our body's yeast. It happens sometimes when we take antibiotics to kill off bacteria that make us sick, but sometimes for a reason we don't know. Bacterial vaginosis, or BV, isn't an STD either. It's an over-growth of the bacteria that live in vaginas. But both need to be treated so your body is balanced.