I got a positive 9-10 dpo using the cheapie tests from ebay, using fmu. they test to 10m/l which is the most sensitive. I ovulated really late that month so don't know when af would have shown up, but usually the second phase was 12-13 days, so this was 2-3 days before af. It does depend on early implantation though, so don't worry if its negative. The benefit of the cheapie ones is that you can test and test without it costing a fortune (to date I have done about 20 after my first positive "just to be sure"........)