Please be gentle with me. I am totally new to all of this. And I am a bit thick. 
I just started temping 19 days ago (I started on day 8 of my cycle). Since then, I have (apparently) ovulated, and I got a score of "good" for the timing of dtd (Or "bd", as they put it. God, I hate that.). And now, I wait. Ugh.
According to their calculations, though, I shouldn't test until the 17th even though my period is due on the 13th (-ish. I have 27-28 day cycles). Am I missing something really obvious here?