baby has no heart beat

So yesterday I had an ultrasound done by a pregnancy clinic because when I took the pregnancy test and the did a ultrasound they didn't see anything so when they did the ultrasound yesterday they didn't see anything no baby so they told me I needed to go to the hospital. So me and my husband went to the hospital they drew my blood did and ultrasound and they told me that they see the baby it's in the right spot the problem there having is finding the babies heart beat I'm spoused to be 9weeks but the ultrasound says I'm 6weeks and 2 days I've been crying like none stop my hcg levels are 4021 as of yesterday which is around 5 to 6 weeks mark my husband thinks the baby is going to be fine I just can't stop thinking about it. I called my doctor I have an ultrasound set up for Thursday  2:45 I've been praying but it's just bothers me to the point where I can't stop crying I've never had this happen to me for