I ovulate anywhere from CD11-CD15. Last month I didn't get a positive until CD 14. Leading up to that they were faint, faint, faint. I've gotten a positive on CD10 (the month DD was conceived), but it's the exception, not the rule. You may still have a few days before you get a positive. Really, though if you've been testing since Wednesday of last week, that means you've been testing since CD 1? Don't bother, you really only need to take them a few days before you expect to ovulate.
For example, the earliest I've ever gotten a positive is CD 10, so I start testing at CD 8.
If you usually ovulate mid cycle on CD14, then you'd want to start testing at CD 10 or 11.
You will only get a positive 24-36 hours before you ovulate, so there's no need to test during your period.