when you run a pregnancy test, you are testing for a hormone called human chorionic gonadotrophin (hCG). this hormone is *only* produced during pregnancy. therefore, you have to wait for the fertilized egg to plant before the hormone is secreted and test becomes accurate.
so what does this have to do with waiting for a missed period? well, when you miss a period, that's a pretty good sign that the fertilized ovum has made itself comfy in the uterus. you can't count down to ovulation, but you can count backward to where it should have happened.
so keep your fingers crossed, and wait it out till your period should show up.
then go get the home preg. test and use it. good luck.
"In God we trust. All others must pay cash..." faw-choon kookie say.