quick question about early u/s's

[*Efjay*]

My SIL has had a ultrasound where she would have been 5 weeks 6 days at the time of the U/S & only the sac was seen no foetal pole etc. sonographer was optimistic & said it can be normal at this point.
But her GP was very negative & only spoke of when she miscarriages etc

is it it possible things will be ok? she is still feeling sick etc, no sign of m/c but she is feeling very confused.