I'm sorry if this doesn't go here but I need some help. Does anyone know what day of my cycle should I start using an opk I've looked on websites that told my I should use them on day 5 and others that said day 11 I just don't know. I've been ttc for almost a year with no luck and I'm worried I'm not ovulating so I want to use an opk but they're not cheap so I want to make sure I'm using it at the right time. Also any opk brands you guys recommend?