Can someone help me read this?

I went off Nuva ring Birth control in October and got my period in November and December on the 24th both months. on January 22 & January 23 I got solid smiley faces on both days and Jan 24 I got the circle for low surge. On Jan 25th I felt twinges in my left ovary area off and on all day so I’m guessing that was me ovulating 48 hours later. I’m trying to understand charting but I still don’t get what the increases and decreases in my chart mean.

Purple opk is Tuesday mornin at 6am

Pink opk is Wednesday at 6am