6w2d and no yolk sac

[brit1612]

I finally am pregnant after 2 ivf's and we went in for our first ultrasound a t 6w2d. They said that we were measuring 5w1d, and they could only see a gest. sac. They did not seem concerned at all. I went back two days later and they saw the same thing, still could not see a yolk sac. This time they were very concerned that nothing had changed in the last two days. That afternoon my beta came back at >5000 (from 3333 two days before). Is there any hope for this pregnancy? Has anyone seen anything similar? Thank you.