B.A.
D.,
If I were you I would wait until at least CD 31, which would be about 10-11 DPO. You may still get a false negative at that point, but if you are just dying to POAS (Pee on a stick) you could start at that point. When I got pregnant with my daughter I got a postive OPK on CD 19 and 20. I was also temping each morning, so I know that I actually O'd on CD 20. I waited to test until CD 33, just because I had been through the testing process for several months and couldn't stand to see another negative, so I waited until I was almost positive I was pregnant without even testing. I usually only had a 10-11 day LP, so when I made it to CD 33, a 13-day LP, with temps that were still up, I just knew...and the test showed positive almost immediately!
Good luck!! If you have any questions you can send me a message!