Don't know when I ovulate - need advice

Mayan
Hi all, I'm new to glow and need some advice. My husband and I have been TTC for three months. AF turned up last week, which was another upsetting day because I really thought we got it this time. Last month we used clear blue OPK (the fancy one). From day 8 through day 21 (give or take) it told me I was high. Each day I checked because I was waiting to see Peak and never did. I think part of the problem is that I can't figure out when I ovulate. I was wondering if anyone has any recommendations on a better OPK or any kind of system that might help!!
Thank you :)