Clearblue Easy Monitor First morning urine?

I got a clearblue easy monitor and it says to test using first morning uring. My monitor is set for 3PM and I know you have a 6 hour window after that but I usually wake up around then because of my work schedule. I usually get up pretty frequently and use the bathroom. Wil that affect my readings? What is the difference? I know it detects certain things but how does it determine what "first morning urine" is? I just dont want to mess this up. I'm on day 11 and still reading low. PLEASE HELP