Opk confusion please help!

So I bought the digital OPKs from clearblue the ones that have a blinking smilie and solid. It says I should have started testing CD 7, but I started at night CD 10 and it showed low fertility. This morning I took it and it showed high fertility (blinking smilie). Could it be inaccurate because I didn't start CD 7 😩 please help!! So this means I'm still not at my high fertility?