Empty sac at 8 week

Yesterday when for my 1st dating scan at kk. The weird thing is when start to scan my tummy she did not say anything at all. Usually they will say this is ur bby head n ect. This i hear doctor will explain.. i got the feeling tat ther is no fetus or growing baby in the sac. So it’s right doctor say i have miscarriage . By 8 week’s should have heart beat. But mine is just empty sac.