What's the earliest you can detect pregnancy through a blood test?

Question

I've heard after one week of conception? Is there an even earlier way of finding out?

Answer 1

Mine was done 2 weeks after conception, which would be the day you should be starting your period.

Answer 2

There's no way of telling earlier than about 2 weeks.  Like the other poster said- the fertilized egg has to implant to your uterus before your body starts producing HCG.

Answer 3

2-3 weeks, that way the egg has become attached and growing and your body is producing HCG.