Ovulation kits question

Hi all,

I did a course of 100mg clomid from day 5-9. I have been taking an ovulation urine test every morning since day 10 with no positives. Today, day 17, I saw in the leaflet I was supposed to be peeing on the stick in the PM rather than the morning.... Does it really matter when I pee on it? Last time I was on clomid (when conceiving my son) I got a positive on the ovulaton test on day 18 only so i'm not unduly stressed but would hate to think I missed my window because I didn't read the fegging instructions properly!

Thanks!