Any hope?

Hi ladies!! This is my second baby... About a week and a half ago I had an ultrasound bc I was having some pain so dr want to do an ultrasound I thought I was 5 weeks on the dot and when I went in tech just saw thickened lining of uterus no gestational sac... I thought I had miscarried or something because I was sure about my date... 3 days later I decided to go to the hospital to get my HCG levels tested .. they were 3,075 and then I got them tested again 72 hours later to see if they improved and they were 8873 ... anyways I’m supposed to be 6 weeks and 3 days today based on my last period .. I’m scheduled for an ultrasound today to make sure the pregnancy is in fact in my uterus... has this happened to anyone else and everything’s been fine? I’m so nervous for my ultrasound today. If you have any hope stories or know someone who had this please share I’ve been so worried