Opk help please?

Do these look like they are changing? These are my test over the last few days looking at the pictures the 4th-6th from the bottom look like they couldve been +opks but i know at the time (before they dried) they didnt look equally dark the one at the top i took just now, does it look like it is getting lighter and i should assume those were the +? I hate to keep BDing every night and then my husband is burnt out and i get a clear positive tomorrow or the next day and im getting frustrated that i havent been able to tell this month! I normally always ovulate cd19-21 but started metformin 3 months ago and each cycle has been a little off since then. Just looking for visual opinions does it look like they are getting lighter or staying the same?