Should I be conscerned with a diagnosis of hetergenously dense breasts with a tiny lymph node partially seen on mammagram?

I am 53 yrs old with a family history of various types of cancer; no breast cancer.  Thank God!  The last couple of years my annual bloodwork has revealed that my white blood count is on the low side of normal.  I have always waited to get the card in the mail informing me of the outcome of  my mamogram. I received the card stating normal.    Wanting to be informed and involved in my own health care I requested a copy of the report and learned that I have hetergenously dense breast.  The report also stated that a tiny lymph node was partially seen within the right axilla.  Should I be alarmed?  Should I pursue additional testing?  If so what type?