Living with uncertainty

Went in for the repeat mammogram and an ultrasound.  They saw the mass but the doctor isn't sure if it is the same mass that they biopsied 5 years ago.  I go back tomorrow morning for another biopsy.  My fear is focused on if it is the same mass, why haven't they so much as mentioned it in the mammograms I've had since then?  At least I don't need to worry about having someone drive me tomorrow.  Not sure if I'll plan to come to work or just take the day off.  If I remember correctly from the last time, it took about a week to get the results from the biopsy.  I don't look forward that that waiting time!