Only gest sac. at 5 weeks 5 days??

Danielle
On Tuesday I had my first us. Thinking that we were 6 weeks 5 days.... We were only able to see an empty sac that measured 5 weeks, 5 days. I'm beyond worried. The nurse did not say much, just scheduled us for another us, next week. Has anyone experienced this and been okay? This is our first baby and first pregnancy. I'm making myself crazy.