Anyone get hcg 48 hour test early pregnancy?

Mesha • Hubby and I have been together 8 years. Have a 2 year old boy and due in June with baby girl!
So I'm 3 weeks 6 days today. Went in Wednesday for blood work and hcg was 39 they said they wanted it to double by today. Mine quadrupled to 155! Is this normal? This isn't an indicator of possible twins or anything is it?