I don't really like charting, but mostly because I wake up at weird times in the night, so then I stressed about times. My doctor didn't say whether I should or shouldn't when I told him. I did it enough where I found a consistent trend with O, so without charting, I feel pretty confident about O by just using OPKs (and in the last two cycles, it appears I've Od at the same time as I always have).
However, I'm starting Clomid in January, so I'll probably start temping again - my O dates will most likely change.