You don't actually need to be late. Unless you ovulated late that month you will get a 99% reliable result on the day your period is due. Many tests will be accurate a few days earlier. Usually women who only get a result when they are late have often had a longer cycle that month and ovulated later.
agreed with Kat2504 - hope you got your answer! i am now 2 days late according to my cycle from last month had some cramping feelings a few days ago and so though the hag would get me but no, no spotting ,no Hag! am still waiting, am so scared to test dont want to get a NOT PREGNANT! so trying to avoid it until the weekend if the hags doesnt appear!!! ive only had 1 good cycle since my mmc in June, AF in july cd36 from day of my op!!!! then aug- 28 days and now nothing!!!today is cd30!!!