You would know if it was a herm. It won't have that puckered look at the tip, like a cow lick almost, it also won't have hairs coming from it, and if it was a pollen sack it would swell up rapidly and split open from several directions and look like a bundle of bananas from the supermarket hanging upside down. I always get those calyxs on the bottom of every node site. They are normal, but when my plants herm that is also where the pollen sacks form. I have hada few pop from the middle of buds too, they are almost impossible for me to find, I don't know how people can see that kind. You will sometimes find them in dried bud, little yellow/white looking spot that resembles something you would find inside a wild flower.