Hi Bright, I've got the exact same problem as you. My cycle is too long so it's almost impossible to track using opk. I usually track for 10 days and give up, usually yielding no positive result.
I've not started using BBT yet, I've heard some mix review about BBT.. As for CM, seriously, I've not notice any difference in my discharge at all. I'm either more dry or wetter, even wetter its also normal cloudy discharge. I never remember having any egg-white like discharge. Like today is already CD21 for me and I still don't see any CM. Either I've not ovulated yet or I'm not ovulating again.
I told my husb to give it a shot for this 3 months, by next Jan if no news we'll opt for clomid. I really don't know how to try naturally anymore when I can't even spot my ovulation.