nervous about my ultrasound tomorrow

This is my first pregnancy. I'm 9w + 3 today. I've only have the symptoms of fatigue, nause ( never actually been sick ), and frequently potty breaks to pee. I have had light cramping after I eat. Around the middle of my 9w all of those symptoms deceased. Like any future mama to be I began to worry that something was wrong. So of course I have searched on the internet for answers. & even tried to find my baby's heartbeat with an app on my phone. Tomorrow I will have my first ultrasound. I'm very excited but very nervous. Any thoughts about why my symptoms reduced? Could I have miscarriaged?