TTC my second after 5+ years

I had my first daughter with an oopsie at 24 years old. She’s now 5 ❤️and my partner and I are hopeful to give her a sibling. We just started ttc and this is my first month using opk to track O… I didn’t recall much change in CM but I had clear positives for opk CD 13-15 (started to taper on 15 on)

We shot on goal CD 13, 15, 16. Is ovulation during the positive / peak or after?? Worried about that CD 14 that we skipped…. Also anyone experience issues conceiving second when they didn’t with the first at a younger age 👵🏻