Help!!

So I found out I was pregnant from a blood test that was done at a hospital on 4-22-16. Then took two home tests that weekend that both came up (what I thought) was positive. Went for my first sonogram today, and the technician said she can't find a baby, or a heart beat. I know I have not misccarried because I have not bled, nor had intense cramping. I'm waiting on a call back from my OB, but I'm still so confused!! We all were under the assumption I was 6w1d today, how is it possible that there is no baby, nor a heart beat, AND have positive tests!? Has anyone had anything like this before??