WEIRD DISCHARGE PLEASE HELP

Ally

For a few months i’ve had this really weird discharge. It’s yellowish and at one point was green. I’ve gotten tested for Std/stis and they’re negative. I’ve taken antibiotics and monistat for yeast infection, and even got treated for bacterial vaginosis. I thought it cleared up but it’d back again today. What’s wrong with me? Mind you this is over 4 months, And i’m on birth control!!