Why does l discharge smell like yogurt?

This is really TMI, but why does my smell like dairy, almost like yogurt? I had a yeast infection and treated it with monistat. But the odour is still strong and has present for a couple of months. The only thing I could find online was that a "fishy smell" means BV. By fishy smell, do they mean that discharge will smell like fish? Or could it be what I have?