B12 deficiency?!...

I was just wondering if anyone knows if b12 deficiency could give a false negative reading. I "feel" pregnant, and I've done a home test which came back negative.
Now 10 days late but my last AF 6/3 wasn't usual for me, lasted 2-3 days and extremely light, I went and spoke with my dr about my symptoms, last period and BD, and she said it sounds likely that I could be pregnant. So going another urine test in the morning.
I've even got people asking if I'm pregnant because I've got a little "bump" appearing. 
Just wondering if anyone else is b12 deficient and has had false negatives?!