I Had Check By An Ob Yesterday, And Performed Transvaginal,

i had check by an ob yesterday, and performed transvaginal, there is no sac seen nor a baby inside, i had home pregnancy test and said positive..i had my last menstration feb 26,she prescribed me to take duphaston 3 times a day, folic acid and multivitamins and she told me to return after 2 weeksto repeat transvaginal, is it posibble that i'm pregnant? tnx