When can i first know if i'm pregnant? what are the best tests to use?

5 days before period: The earliest a pregnancy test can be positive is 5-6 days before when your period would normally start, or about 9 days after conception. Most of the over the counter pregnancy tests will be very reliable by the time your period would normally start. I don't know which brand name is the best, perhaps someone else can answer that question.

1 week before cycle: Most home pregnancy test can reliably detect pregnancy a minimum of 1 week prior to the date you expect your cycle to begin. Sometimes it is difficult to read the pregnancy tests with the lines, therefore, i recommend the digital pregnancy tests.