When do you test?

Kristin • Trying for #2!
Hey ladies! My husband and I just started trying in January and hopefully this is our month!  I bought an OPK for the first time. It has 20 test strips which, I think, is making me more anxious to see that positive for the LGH surge!! Anywho, what day do you start testing for pregnancy? I know it takes quite a while for implantation, but waiting is so hard!!!