Does a +ve opk indicate top fertility day? what's the max time aftr that for conception to happen? how reliable are opks?

Cheeta,: They are fairly reliable at detecting your lh and estrogen surge. The surge occurs when you ovulate so time relations to the results.

1-2 days.: Ovulation prediction kits detect the lh surge that produces your egg release within 24 hours. As the egg only lives for ~24 hours after its release, conception has to occur within 1-2 days of the positive opk. Take Folic Acid 1 mg daily and best of luck!