Any one in my shoes

So today I went for my dating scan which I thought was 8 weeks so she was looking around and around and said she only sees gestational sac nothing else she was looking at my left side but I knew from previous sono my baby was in my right so I told her look at my right she wasn’t listening and kept actin like there’s no baby I ended up crying and had to show her my previous scan and they she moved the probe to the right and guess what there was a baby moving and the hear rate was 150 but what confused us is why is there one empty gestational sac on my left and then the one on my right is my baby 7 weeks 2 days .. I mean I know twins aren’t that far apart . She didn’t even have the answer herself about this she was just looking and looking but good news baby heart rate went from 110 last sono to 15o and baby moving and everything was good but the left gestational sac is question mark