White crusty gunk in nipples?

So I’ve had this for years, but my nipples get this sort of white gunk in them? (I’m 24, never been pregnant and not pregnant) My nips are a bit inverted (not a lot), does anyone else have this? And what could it be? It’s not a liquid, more like crusty gunk? Idk how to explain it lol. Like I could pick it out with my fingernail.

I have an appointment with my gynecologist next week to check but I just keep worrying about it. And I googled it which was probably the worse thing for me to do.