Opks - can you test at any time of the day?

Just wondering. I have the strips which i find hard to read. I was thinking of Googling a chart for it to see if I can decipher it. I have the Answer brand. It's night here and i need to go pee. Can i pee on the strip and get an accurate reading at this time? Will it make a difference? I'm supposed to be at my most fertile today according to Glow.