Second dating scan

Rachael

I've had a second dating scan as they couldn't find my baby in the sac in the first one. The sac measured 6 weeks 1 day so it was 4 days out.

This new scan yesterday has my baby measuring 10 days behind what I should be.

Should I be worried? A few girls I know had this happen and miscarried a few weeks later.

My baby's heart rate was 127bpm. According to my dates I am due 30th Sept but according to their scan I am due 9th October. Thanks