SCARED Nothing on ultrasound high hcg though

I found out I am preggers on Monday. I went to the doctor on Tuesday and my hCG levels were 2800 but they found nothing on the ultrasound. I should have been five weeks exactly. They told me to come in tomorrow to measure my hCG and do another ultrasound. They said I might have any ectopic pregnancy or have already had a miscarriage. I’m so nervous because I really want to be pregnant. We have been trying for two years. And this is the first positive. Has anyone else gone through this and everything ended up ok?

UPDATE: we saw a sac on the US on the right side of my uterus! but it’s still early.... they want me to come back next week to make sure there is a baby in it!