I was able to see the embryo and heart beat at 7 weeks but my sister is also pregnant and wasn't able to see it until 8 weeks she is now 20 weeks and everything is going great. Everyone is different and your hcg levels loom great.
7weekd is too early. I went to my gyne first time last Thursday! When he saw me excited that he was going to do an ultrasound he warned me that I will only see the sac. I am in my 7 week, starting today and according to the pregnancy app the foetus is just 1.5 cm approx
You may have ovulated late and aren't as far along as you think. Your levels seem great though! Your doc should be scheduling another blood test in a couple days to check that your levels are still rising and another ultrasound in a week or two to get proper dates. Request this if they aren't. Good luck!
Are they repeating another ultrasound in a week or so? Or re-drawing more blood to check you hcg levels are going up? I wouldn't worry yet, your still a little early yet.
Its best to see where they are from your next draw. If they are going up that is a good sign. Seems like its possible that you are not as far along as your Lmp suggests?