advice needed

Okay so I screwed up my cycles when I posted them on my other long winded post.

Here is how they have been (lengthwise)
March:30
April: 31
May:28
June: 29 EWCM day 14. (this is the month we started to try and my IUD was removed)
July: 26 EWCM day 12
August: ? No AF yet. No EWCM

besides OPK's is there anything I can do to figure out when I O? We have been BD'ing between day 7 and 16 most cyles give or take a few days.. We are switching back and forth between every day, and every other day.

Re: advice needed

Temping, observing CM, and OPK's are the methods of identifying O that I am aware of. OPK's and changes in CM predict O while temperature rise on a BBT shows that it has already happened. Good luck!