Hello everyone I found out I’m pregnant April 5th and have gone to the ER that same day my HCG was at 865 , then Friday it was 1,798 & today it’s 6,512

My concern is the first ultrasound they did they could only see a little shadow

The second one they seen a “empty cyst like” thing and told me it might be the sac and will start developing , my husband took a picture of the ultrasound the last time we went when it was at 1,798 :

Should I be concerned ? (Also we dont know how far along we are) my last period started in April 6