I start testing on day 7 or 8. I use PreMate from Camelot Farms (www.camelotfarms.com), and I think 4 out or 5 pregnancies is pretty good, considering the problem getting pregnancies, before. #5 is a problem and I am going to try 1 more time. She has missed 3 times.
Depends on your lines... The girl I was hoping to breed comes from a line that ovulates VERY early. I took her in on day 7 (had been checking her everyday) and she was already a 19. So, next time, I will be taking her in a few days after she shows color. My other girls, I took in at day 7. Good luck!
I usually take them in ~day 7, but we start w/ a vaginal smear. If she's well on her way to cornification, we'll do a progesterone, otherwise we'll wait a couple days more. Most of my girls don't ovulate til day 14 or so anyhow so this is more of a check to make sure I caught the beginning of the cycle.