OPK Help

Kayla

I need help! This is my 2nd time ever doing OPKs. CD 1 was April 21st and I took Letrozole CD 3-7. To me CD 16 looks like the darkest I have gotten and last night I was so nauseas and had bad pain on my right ovary. I am wondering if I missed my surge? Any advice wpuld be appreciated!