I had my 2 yearly mammogram last week. Always been fine . I have a letter for a callback to their main breast screen building. Nurse said "not suspicious" but a grey area that needs to be checked. Takes 3 hours? What does this mean? . I'm really worried, as many of you have been through this, can you explain? Panic stricken! . I'm in Adelaide Australia. I have an idea what they do while I'm there,  but what are the chances it's nasty? Please help.