clear blue digital sensitivity

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Hi ladies! Yesterday (at 10 dpo) I found out I'm pregnant using a First Reaponse Gold Ditigal. This morning (11 dpo) I took the clear blue digital test and it also came up positive. 
After a second trimester Miscarriage in March, I am feeling both excited and terrified. 
My question: Don't clear blue digital tests require twice the amount of HCG than FRER? If so, how is it my HCG doubled in less than 24 hours? 
Extra details- I had a negative test on 8dpo and my O date was determined by an OPK
Please help! This is one confused/excited momma.