Your tests came back normal likely because you had minimal / normal amounts of yeast in your blood and stool. Sometimes it's not so much the amount of yeast that is present, rather your sensitivity to it, which is what causes your symptoms. Your problem still points to a candida infection. If you have issues when eating sugary foods or foods with white flour, but they stop when you go on an anti-candida diet, then the problem is likely candida.
Vaginal discomfort is a common problem for some women after consuming candida-feeding foods. It doesn't mean eating those things causes a full-body overgrowth of candida, it just means they're more sensitive to those foods and more prone to those types of issues because of it. + If that's their only symptom it's normal and likely their tests would come back normal.