The reasoning is this, we go to the hospital with the purpose of detecting serious diseases and tumors. Breast examinations usually require a physical exam, ultrasound, and mammogram, or even MRI, by an experienced specialist to detect the presence of a tumor. If the physical exam, ultrasound, and mammogram do not reveal a tumor (benign or malignant), then there is no major problem with your breast. You can then relax. It is important to point out here that hospitals and doctors, ultrasound and mammogram themselves are of different levels, and the level of your district hospital, non-breast specialist, non-specialist ultrasound doctor, the advanced level of mammogram equipment, and the level of mammogram reading doctor are all directly related to the reliability of the final conclusion.