Community post

Generally when you start using OPKs will depend on your average cycle length. For example: I normally ovulate around CD15-20 so I don't start using OPKs till CD13.

If you have a ~28 day cycle I'd start using OPKs around CD10.

Also it's probably fine to just test once a day till you notice the test darkening. Once it starts to darken I'd switch to twice a day. Maybe even 3 times a day once it's "nearly positive."

Be sure to read the directions on whatever OPK you're using. I know if you use the Clearblue Advanced Digitals they say to use first morning urine since they also check for Estrogen. Traditional OPKs (such as a basic Wondfo dip stick) suggest waiting till around 2pm to test.

And of course if you know you're going to test try to reasonably restrict fluids. Nothing crazy but also don't chug a bottle of water an hour before or something.

About 3 days before the middle of your cycle. My cycle is 28 days , so I should start (according to what the test says) on CD 11. I normally have a positive OPK on CD 14.