Blighted ovum or too early?

Kieren

9 dpo bloods were 8, 11 dpo they were 39, 16 dpo 298, 20 dpo 1898 and then most recent bloods 10 days later at 6+2 or 30 dpo was 47000. Had a scan and saw a sac measuring exactly too my period date. I've had no bleeding just cramping. Women who have had them, how was your pregnancy? And hcg etc?