they don't work that early for a lot of ppl TD, Sorry. I used them when testing with Jess, I didn't get a +ve till 8wks PO. And I know a lot of ppl who use them and don't get +ve's till 14DPO. I have also got a lot of evap lines using them. They are the ones I buy most of the time, but they are not as reliable as some other brands I think...