Advice ! 12 days late BFN!

Ashley
Hey ladies !  I am officially 12 days late and still getting BFN. This is my first time TTC and I have never been more than 4 days late.  Has this happen to anyone?  If I do not start by Sunday I am going get a blood test.  I'm having symptoms such as sore boobs and random spells of nausea. Any advice or support would be helpful !  Happy thanksgiving !