Well it does sort of, lemme give you a quicky run down what I've learned...
We surge in the am, but it doesn't show up until the afternoon so the best suggested times are between 11am-11pm to po-OPK-s.
However, if you've been drinking allot of water thru the day you will have lighter test sticks. So if you've not peed in a while it will probably be darker with the more concentrated the LH is in your system kinda like hpt's.
The closer I get to O time, I will poa'opk 2-3 times a day... just to be sure I catch it