3dpo positive opk

Danielle • Mommy of 3 girls ages 12, 6 and 4

I am on my first round of letrozole and I ovulated Saturday . For sure with tracking bbt and ovulation and a blood draw . I am 3dpo and my lh surge dropped down to like .60 or .7 and this morning it’s spiked up to high again. What is happening ? Is this normal? I also knew when I was ovulating due to the feeling of my ovaries but today I feel fine . I use the premom app and test strips !