My baby girl hurt me very bad three times while nursing today, she hadn't done that. Why! I hope it…

My baby girl hurt me very bad three times while nursing today, she hadn't done that. Why! I hope it stops, because its so painful when she does it. it's like she nibbles or bites down on my nipple, idk what it is exactly she does. Idk if its because she's getting older, or what. but please baby don't do that 😥😢