Dayum, I had that happen to me once. I went ahead and took one for the team and my little head thanked me later.
I always shower, bush my teeth, mouthwash and deodorize thoroughly just before leaving for an appointment. I would never want to present myself less that fresh for a provider. Expect them to do the same. Still, I always do the finger test before DATY. Only had a few instances where I had to leave...