<prompt> Gestational sac can be seen earliest on transvaginal scan at4- 5 wks5 - 6 wks7 - 8 wks10 wks  <response>: Gestational sac Cardiac activity Transvaginal sonography 4 weeks 5 weeks Transabdominal sonography 5 weeks 6 weeks Please note: in exams the same information may be asked as Which week gestational sac is seen ? the answer choice maybe given as 5th week. so please realize that 4 wks some days is actually the 5th week. 