Everything that the ladies said above....

Also keep track of your CM... it usually is a sign that you definitely should be using the OPK's around that time.... You should be expecting the "+" opk a few days after...
I use the clearblue digital OPK... shows me the smiley face so I can be for sure that I "O'ed"... but I think i'll be jumping over to wondfo because you get more for the money (thanks ladies

) ....
Good Luck!!!!!!!!! Catch that Egg.... (sneaky little boogers... )