6w2d is this normal? TW miscarriage question

She barely could get a glimpse of the yolk sac. But she measured and said I’m around 6w2d. She said I could come back in 2 weeks since we weren’t able to see heartbeat or baby. Is this normal? Would she had been able to tell if I had a miscarriage? I had 0 signs of a miscarriage but am paranoid.