Nervous for next ultrasound! Only sac at 5+3

I had a mmc in May at 8 weeks after seeing the heartbeat. So I ended up going to the ER Friday because I’m crazy and got worried after seeing some tiny bit of pink when I wiped. It only happened that one time. The ultrasound only showed a sac but my hcg has risen great up from 103 at 4+1 to 5,722 at 5+3. Of course I know it’s probably normal but it still worries me. I tracked with opk and temping so I know when I ovulated. My scan with my doctor isn’t until September 3rd. I’m slightly worried over here. Any advice helps