I've never done clomid, but did have to report the "3rd day" to my clinic for a couple IVF treatments, and had to start bcp. They always told me that spotting isn't AF unless that is normal for you and you're a really light bleeder. Since I tended to spot before AF, even when I took Provera one time, they said to wait for "full flow". Since you have to wait until day 3 to start the clomid anyway, I would wait until it's a bit heavier than just spotting to count it as day one. When it comes to AF, spotting, timing and treatments, it isn't an exact science, so a day or two, shouldn't make that much of a difference. Good luck!!