What Causes Pregnancy Symptoms And Negative HPT With History Of Tubal Ligation?

I had my tubes tied in 2013, I am having many signs of pregnancy now. I have gain weight lately and I usually stay at a set weight. I ve had nausea and vomiting, and sensitivity to smells. I have taken 2 pregnancy test and both have came out negative. So my question is would a pregnancy test come out negative because of my tubes being tied?