Pregnancy and pregnancy test

I'm not sure where I should post it but I didn't want it to be in the "Am I Pregnant?" Because I'm not exactly asking if I'm pregnant. I'll take the pregnancy test. My question: For those who receive their conception right after their period, when do you take the pregnancy test? Do you still test it when you're on your missed period or do you wait until 6 weeks? Or do you take a special test for this?