OPK questions

[Rowellen]

I had a tiny bit of EWCM this morning, so I decided to do my first ever OPK (tricky since I'm at work) & it's got a faint line. Definately a line but much fainter than the control line. I think that would mean that I will O soon but not right now? Is that right? It seems too early since I don't expect to O until Sunday. Does any one know how long it takes to O once a faint line appears?

Also, does any know if PCOS effects the reliability of OPKs?
ETA: I am pretty sure I am ovulating each month as I take Metformin & my cycles have regulated to around 36-39 days although I have had one 33 day cycle.

TIA