Birads 0 with no signs or symptom of cancer on mammogram means incomplete meaning the mammogram was done incorrectly? or what does it mean exactly?

Additional tests: Incomplete means additional studies are required. Possible reasons are that the radiologist wants a magnified look at a specific area, that the breasts are dense and a sonogram is indicated, or that old studies are required for comparison to make sure there are no changes. It does not mean it was done incorrectly.

Not incorrectly. . .: The mammogram may have been limited in it's ability to see an area of the breast based on the two views they took. So "bi-rads 0" just means you need additional imaging to clarify an area that may be obscured, but not necessarily suspicious.

Incomplete: It means that the mammographic evaluation is incomplete based on the screening exam. The radiologist has identified a potential abnormality that requires special extra views, and possibly ultrasound, to completely evaluate and render a final diagnosis. Many times it turns out to be nothing, sometimes it is something that needs a biopsy.