So many emotions

I'm scared. I am sad. This pregnancy felt different then my pregnancies with my two daughters. I went in for an ultrasound 6wks 3days. Both ab and vaginal. Doctor said she seen a sac and everything looked healthy but no heartbeat yet. She said it could be too early. I cried on the way home. Silent tears but so many.. I go back in 8 days. I will be 7 weeks 4 days. My husband says not to worry but it's hard. I want everything to be good.