The kits usually have instructions in them. I usually start testing about 11 days after my last period. (the kits usually have about 6 or 7 sticks). When the lh surge is detected, the stick will show a line, or a second line, depending on the type you are using. When you detect the lh surge, you are due to ovualte in appox. 24-48 hours so you should have intercourse over the next day to four or so days, just to be sure. All kits are probably different so read the instructions. If you don't detect the lh surge, continue testing daily until you do. (that is why there are 6-7 test sticks). Also, most of them say to use it when you first wake up in the morning or try to hold your urine for four hours or more. Good luck to you!!! I hope this helped.