At my hospital you have someone different as you have to go round the other side of the clinic, its weird here lol. Well its nice to have a suprise, i couldnt keep this one a suprise i was in too much suspense haha! But yea im pretty sure that 20wk scan is shorter, maybe im wrong but mine was only 1/4 of the time that my 12wk one was. And he stopped the scan and went back to ask me if i wanted to no the sex for sure then he spent 1second saying "theres his willie" lol x