IVF and measuring behind 1 week

Brittany

Hi! I’m asking for a friend. I have a friend who is going through IVF and she had an embryo transfer and she got pregnant. Today was her first ultrasound and they said baby is measuring a week behind. They said it could have implanted late or could be a miscarriage. They go back in a week. They are obviously very upset and I was just wondering if anyone has any experience with this or advice. Thank you so much!