Hey, I have a question about the clear blue fertility monitor. I have just ordered one along with the sticks & it's arriving tomorrow. I will be CD7 tomorrow and as you have to use first urine I won't be able to use it until CD8 which is 2 days after the window. Do I need to wait a whole month to use it or can I over ride it? Bought it before I realised you need to start early as I usually start OPKs on CD9