Hi Angel
Fortunately I bought 100 OPKs from off the web - I have not noticed them getting darker but it has only been two days and very very faint and very faint are difficult to see the difference IYKWIM.

I also have EWCM at the moment so am taking that as a good indicator. I was concerned as my cycle last time showed a couple of patches of EWCM but no temp shift - hence no ovulation.

Anyway I will keep monitoring those lines and hope they get darker.
Thanks again.