To opk, or not opk?

Laura

Alright, so my obgyn suggested that I start using ovulation predictor kits. Once I show an LH surge, we should do the deed the next few days. But I keep reading all this stuff about there's no way to tell when your surge began, and that you could have already ovulated before the positive opk.

Are there any tricks to this trade? Any big no-nos? I just don't want to waste a month by screwing something up.