OPK questions please help

I only start using opk this cycle. So it is my first time using them. I've been testing after AF goes. Today is CD9. ( I normally have a 30-days- Cycle) I've been testing on CD6. 7. 8. 9. They are all negative ( which I understand ).

My question is is it normal there's only control line there. No other line at all. Not even faint. Nothing at all. Just the control line is there. Is it normal ?

I've seen other people post their opk photo and I can see from faint to positive. But mine has no faint line at all. Only control line is there. Which worries me a little.