Sonogram?? Im Pregnant?

I just went to the Doctors on the 23 of Oct because I haven't had a period since July..The took a pregnancy test and the drew blood, and also the did a Pelvic Sonogram, and a Belly sonogram and all my test came back Neg..everything was Good....My doctor said even though I haven't had a period I can still ovulate and get pregnant .So for about 2 weeks I been feeling really tired..sick, hurt so my husband bought me a home test and it was Positive..I was really shocked and happy because we been trying for over a year and I just went to the doctor two weeks ago and everything was neg..even my sonograms...So I was just wondering if that was possible when all test where neg..and If I am will the home test be Positive if im only 2weeks along cause the night of the sonogram we had and other nights after that LOL LOL (T.M.I) LOL