How soon

[MrsDAB]

How soon after conception can one test? Or how soon do you know before the first missed period?

[Lastminutemama]

That depends on the amount of HCG level ones builds up. I know womens who had a postive test 4 days before their expected period, others had to wait for a week past that date. I guess most home tests give an adequate result on the day your period is expected.
By the way: a regular ovulation test gives the same result when you use it around the date of your AF, so might be useful when you ran out of pregnancy tests.:)

[jifnif]

i would say at least two weeks!!  i have tested positive up to 5 days before expected af.  :)  

[shesherm]

I got a positive 4 days before my period was due but everyone is different.  good luck

[pcarsey]

some may not find out until after their missed period, some soon as 5 days ahead, best to get a quant blood test