Weird discharge...

I don’t know if it’s a yeast infection because this never happened in the past with yeast infections but I’m not sexually active at the moment and haven’t been for over a year, I have no STDS. But for the past couple days Ive been getting green discharge crust on the lips of my vagina. No odor, no pain, no redness or anything just the weird crust. Any reason why? I’m nervous.