OPK--When should I use these?

[magpie]

I got a bunch of OPKs to use this cycle after last month's long, unpredictable one. Last cycle was my first one off the pill and it was a marathon 47 days. From my chart and just the general timing, I am pretty sure that I ovulated on Day 32. FF, of course, is predicting that ovulation will occur on Day 32 again this cycle, but I feel like it could happen at any time, since my body is still working itself out after bc.

Long story short, when would it be reasonable to start peeing on these things to "catch" ovulation this cycle? Obviously, we'll also just try to do it a lot and I'll monitor CM and all that jazz, but I'm trying to cover all my bases here to catch that fertile window!

[KaraOrNot]

I usually start around day 7 or 8.