No positive opk!

Lauren • I`m 25, been with my hubby 8 years, married just over 1 years, ttc 1#. Sending baby dust xx
Hi lovely ladies, I've been monitoring my ovulation for the past 10days, my cycles average from 37-40 days, and I haven't received a positive opk, the only line I'm getting is the control line now. The second line never got as dark as the control line 3 days ago. Has anyone else experienced this? Can I still full pregnant? According to glow, tomorrow should be my peak day. As it's been quite accurate before. Any advice? Xx