When I found a small lump under my breast, the gyn doctor sent me right away for mammogram where they found something which led them to giving me ultrasound as well. (The gyn doctor set an appointment for the surgeon for the next day as well) The radiologist said "Let's check it in six months" and I'm so glad I didn't listen to him. I am one of the ones who didn't fall into the 80% benign bracket and it turns out I have invasive lobular cancer and the surgeon was doing surgery to remove the lump within 5 days. I've written about
it some on my journel
http://rubyshooz.wordpress.com if you'd care to know more, but sometimes, just going to the doctors and insisting that they/we need to be more aggresive about
finding out what the trouble is makes the most sense - that's how it's worked for me so far. Wait and see when it comes to our breasts can be an awful experience.
Best wishes to you!