I used two first responce tests one when i was due in 3 days and one when i was due in 1 day, both negative. Then just thought my period was late so didnt do another test until the doc told me too when i was 6 days late! test was positive straight away, think it cost me £5.50 for two little sticks!!! then did one on the 7th day, showed a bit faint, so went and got a clear blue, which showed up positive b4 id even finished peeing!!!!!