am I going to ovulate?

Sussie
I got off the pill about a month ago. I was suppose to be my most fertile since last Tuesday . It’s is now Sunday and my window is over tomorrow. I’ve been testing with Clearblue ovulation kit since my day 6 of cycle and today I am on day 18. I see no happy face on the test and I’m starting to become discouraged. Should it be that I will ovulate later?
Thank you for your advise :)