Opk help!!

Kelsey

So my first time using opk and not sure what to think. I started testing the day after my period ended so I made sure I wouldn’t miss anything. My app predicts I will ovulate on Sunday but my LG surge seems to be fluctuating a lot. I’ve started to take two tests a day. One the the morning and one around 4pm when I get home from work. Does this normally happen? My cycles are very regular! Any advise would be great!!!