OPKs are cheap ones from Amazon any good?

[onefunkymama]

Anyone tried the OPKs linked? The Clearblue ones are pricey and I wondered about trying these first www.amazon.co.uk/Highly-Sensitive-Ovulation-Fertility-Strips/dp/B001G7P62S/ref=sr_1_1?ie=UTF8&qid=1378191202&sr=8-1&keywords=ovulation+predictor+kit

Not a stupid question at all. It really depends how long there is between your first faint line and a positive.
Assuming there are 18 hours between your positive and O then the three most fertile days for DTD are the day before the positive opk (O-2), the day of the positive (O-1) and the day after that (O day). I would add on a day either side to cover all bases.

When I got a positive opk on cheap amazon ones I wasn't 100% sure as I was getting faint lines anyway. Clear blue confirmed it though. Next month if no bfp I'm just using clear blue simply because peeing in a cup and waiting 20 minutes is too annoying for me! I need instant answers