what's your HCG Level?

B.C
I saw my OB yesterday at 6weeks and 5days and my HCG level was 20,347. Dr told me is normal. 
From my last pregnancy that ended in miscarriage my HCG at 6weeks was 840 and was really low.
I have been dreaming of twins and I can't wait for my First Sonogram which will not be until 6/26. Any one have a high HCG with twin babies or can single baby HCG also be as high as mine?