confused about the digital weeks test

You know the test that tells you how far along you are. How can it tells someone they're 1-2 weeks I thought it'll be too early to test by then. Today is my ovulation day and it says I'm two weeks on this online calendar. I'm not testing until after is late.

02
    12/17/13
    Oh no I didn't take a test I was asking about the test.
    0
    About Nichole powell
    Current: Fremont, California
    Birth: January 20
    On Moms.com since: Nov 30, 2013
    Hello I'm Nichole and I am 30 years old. I'm married we have two girls and 1 boy . Jani is 9 and Ma'ryjha is 7 and Kingston is 2years old. I'm from California. I'm loving my life and I'm very blessed to have a wonderful family.