2nd missed period and still showing negative..... back to the docs?

hey all. So my last period was at the beginning of November. Did pregnancy tests when I missed in Dec and went to the docs for a blood test but all negative. Period was due again on the 2nd Jan but still nothing. took another test this morning and showing negative. I have never missed a period in my life. what do you think, back to the doctor? I'm really hoping I am pregnant but my body just isn't showing the hcg for some reason. thanks for reading x