Have I ovulated maybe?

New to tracking bbt and opk. Do you ovulate on your first opk positive? Or at the darkest "peak". I know it might be too early to see if I've ovulated, because you need 3 high temp days right? Temp was higher today, so wondering if I ovulated yesterday. I had positive opk yesterday, lines were equal, this morning 1st line was dark, as in my peak. Thanks for the help!