You'd have to pee every day, at the same time, with the pee ones. And according to TCOYF, they don't always tell you AHEAD of time, so I think for your purposes, they might be too little too late.
The site I linked says the saliva tester is 98% accurate?
That's what I'm going to get (TTC rather than avoiding) and perhaps some cheapie ovu pee-sticks...my son is 23 months and still nurses a TON, and my other signs of ovu aren't reliable right now...so I'm checking everything (except temp, I can't wake up at the same time, and I can't guarantee I won't have been up just an hour before wake-up time).
Anyway, I think the pee tests wouldn't be right for your purposes...also, you have to buy things for it, and they are intended not to be used every day (so you would be increasing your expense) (at least I THINK they aren't meant to be used every day), and YOU would be needing to check EVERY DAY, right? I'd go with saliva.
Have you looked at the ovu test info on
www.peeonastick.com. It was there that I learned that the pee strips aren't perfect, and that you might miss your surge of hormones, etc etc...the ferning test with saliva just seems better for my purposes. And maybe yours.