cancer detection and tests....who to trust?

It is kind of backwards, but doctors do not often order mammograms on patients in their 20s although I had my first mammogram at 28 due to a lump and it was well visualized. The decision is up to you. Your doctor should have explained their reasoning to you. If you were a friend coming to me with this question, which happens fairly often to me, I would not give an opinion without seeing the ultrasound report. The techs suggestion would matter little to me I would want to know what the radiologist says. Their opinion is what matters most and is what the other doctors usually follow.