Ovulation cm

So my green dot ovulation starts tomorrow on my calendar. I took a test strip few hours ago it was negative. Is it normal to get ovulation cm clear and stretchy right before ovulation starts? Or am i supposed to get it on my peak? I been testing everyday with opk and havent seen a positive its been very faint and negative. I just hope this is normal before my peak because i want to make sure i didnt miss my chance. I will continue to opk because last month i reached my peak on cd16. I am Cd10 today. Thank you ladies