Normal ultrasound for 5/6 weeks?

I had a vaginal ultrasound this morning. She saw the gestational sac but nothing else, no yolk sac or baby. From my dates I thought I was about 5 weeks 6 days but she said more like 5 weeks. I had a scan 12 days ago and there was no visible gestational sac, is it a good sign that it’s there now? First time mum and ttc for a long time so very anxious! Thanks in advance.