Im really concerned

Victoria

So i.am supposedly 6 weeks 5 days pregnant based off of my last period. My HCG labs were 892 to 1107 two days apart. I got this ultrasound done two days ago. They said there was no yolk sac or baby. Is it possible I ovulated later than we think? Or could this be something is wrong. This would be my 6th loss and im just really worried!