Ok...I'm incredibly confused. Ball pythons are not supposed to have pits on their lower lip, are they?

I was just taking a close look at my BP and noticed something odd. She appears to have 4 pits (2 on each side) of her lower lip, near the back in the same place that a gtp or something would have. I've been looking all over the place, and I can't find anything about this. Is this normal, rare, or unheard of?