Looking a week and a half behind help!

So I went in for my first ultrasound yesterday and should have been about 7w1d according to my reproductive endocrinologist. Well when we did the ultrasound she found a sac and it was only measuring 5w3d and there was nothing inside, although you did see a blur in the background which she said something is trying to grow. I got my hcg levels and they are 8,863. I’m so scared we are going to lose this baby that we have been trying for a year to conceive. Has this ever happened to anyone and the baby ended up growing fine or did it result in a miscarriage? I have an ultrasound next Thursday to see if any progress but this wait is going to be so hard 😢.