Question? Opk

This is my third topic but I can’t update the other ones for some reason. Anywho.

Started taking opk for first time yesterday. My period is supposedly due tomorrow. But I skipped last month so idk if I’m getting it this month since I’m super irregular. Currently cramping kinda bad. Not unusual but then again my period is kinda wacky so idk what to expect. I am TTC.

My question is how long do Lh surges last? How should I interpret he results? Should I use a different brand or is clear blue accurate? Should I take a pregnancy test since it’s technically too late for me to ovulate(since my period is supposed to start tomorrow)? (I heard that OPKs pick up HCG as well)

Lol I’m new at this!

Top photo is 8/26

Other 2 are 8/27. One at 7:45 am and the second at 12:30 pm.