High hcg at 4 weeks

Ann

My last period was 4/17 but I know I ovulated on 5/9. On dpo 11 I had some red tissue come out and next day I tested positive. I had some mild cramping in my side. I checked again on dpo 15 and was positive again for pregnancy. My doctor says I’m 5 weeks this week because they go off last period. In my head I think I’m 4 weeks since I ovulated just over 2 weeks ago. My hcg level this week at 16 dpo was 1252 and 18 dpo 3030. They want me to come in at 6 weeks for ultrasound. Has anyone had this high level early? Should I be worried for a molar pregnancy? Or twins? Seems high based on the charts if looking at 4 weeks and it more than doubled. Thank you!