Need some info

Brittney
Today was the first day after ttc for 4 years that I have ever gotten ewcm (and alot of it). However, I am using the clear blue opk and I didn't get, or have ever gotten, a smiley face or a positive. I have regular 28 day cycles and currently on day 17 and have been testing since day 11. Has anyone ever experienced this before where you have signs of ovulation but negative opk?