Clomid CD14 and OPKs

Caitlin
I was just wondering how fast other people saw the lines getting darker on their OPKs. 
I'm on clomid CD14, and I've been testing since CD11, I can see vvvvfl that when you line them up seem to be getting a little bit darker everyday. Do they say faint until closer to ovulation? And then boom dark! Or should I expect it to be more gradual and I just need to be patient? I think O will be New Year's <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>/day, but I didn't know if it should be darker by now. 
If they start getting darker I plan to use digitals to confirm O day. 
First round on clomid, first time using the cheapie a for opks. 
Thanks for the advice.