Palpable breast lump doesn't show on tests

[Jb1954]

I am a post menopausal woman with a small hard lump in my breast. (I do beading and to me it feels like a size 8 seed bead..2-3mm) I can feel it, the ultrasound tech felt it and a Dr. felt it but it does not show up in either the mammogram or ultrasound.  Familial history is mother and 2 sisters all have had breast cancer.  Mother and one sister did not survive, the other sister is 20 years post surgery and now has lung cancer.  Two had receptor negative and one was receptor positive.  With this family history I have been told MY risk factor is not great enough to warrant an MRI or biopsy.  Should I get a 2nd opinion?