6 weeks empty sac

Due to some scares I had an early ultrasound today. I’m believed to be 6 weeks and 2 Days. However the sac is empty. The Tech thought maybe she seen a yolk sac but couldn’t confirm it.

When she went to measure the sac it wasn’t even registering which she thought maybe I’m not as far along as we thought. She also used another measurement which isn’t as accurate as the first one she used but it measured 6w 3D.

I’m so worried now. I have my first appointment with my actual OB Monday morning. She’ll do another a ultrasound but I’m so worried now because I started reading about empty sacs and blighted ovum has jumped out at me. She was able to rule out ectopic.