I have white stuff in my boobs but i never had a baby i don't know if its cellulite but is it cancerous and is it dangerous i'm 29.

Get it checked out: This is probably benign and may represent drainage of a cyst or obstructed duct or milky duscharge. In any case it should be checked out. Diagnostic imaging, cytology or blood tests may be required. Underlying breast tumors or pituitary tumors may need to be excluded.

Breast discharge: It is not rare to have a small amount of discharge from the nipple. Most of the time it is benign but you should have a professional look at and examine you to see if any thing else needs to be done.