What can alter ovulation predictor results?

[minkajane]

I am showing several signs of ovulation - ovulation pain, cramping, EWCM - but the ovulation predictor says no. I forgot to test yesterday, the day the EWCM started, so maybe I missed it. But if I didn't miss it, what could alter the results or cause it not to register ovulation? I'm not on any fertility meds right now, just Metformin, but I have PCOS. Could that mess with it?

[Lousli]

You can just miss the surge if you have a short surge. Your urine can be diluted if you're drinking lots of fluids. Can you take another one later today after holding urine for a while? If you have EWCM, go ahead and BD to cover your bases!

[MaerynPearl]

You may not have even had your surge yet, some women can have ewcm for several days before O happens, so you could have ewcm for a couple days before you even catch your surge.

[finnegansmom]

I actually thought that PCOS can make you test positive more often...
You could have missed it, or maybe you are gearing up?
I have ewcm for a week generally before I got my first +.
I buy the sticks in bulk and start testing around the 2nd day of fertile cm...