It's normal to be so worried, honestly I'm 36 weeks, and I've still not lost the excessive worried feeling. Any time I feel like I might not have felt him move enough, I panic. He's been fine and within percentile for his development, but everything still worries me. Just comes with the territory, you can't see them, and you just have to take doctor's word for it that they are okay, until you start getting movement, and even then you tell yourself that something might not be right. lol I didn't schedule for an early ultrasound, but I did schedule for one before my 20 week gender confirmation, and being hospitalized for preterm labor, I begged for them all the time. Good luck! I'm sure everything is fine!
This is normal. I had the exact same thing happen to me, I lost all of my symptoms at exactly 9 weeks and I was so worried that I had a missed miscarriage. But I was told that during this time, the symptoms go away (for now) and you start feeling better. Try not to stress out!