Testing for ovulation is one of the most popular ways to find out if a mature egg has been released from the ovarian follicle into the abdominal cavity. The test reacts to a sharp increase of the luteinizing hormone in the blood, saliva, and urine, which, as a rule, precedes the release of the egg from the follicle. If you have a regular 28-day cycle, start your testing on the 11th day of the menstrual cycle. If your cycle lasts longer than 28 days, then you can do it 17 days before the anticipated first day of your next menstrual cycle. 

You should do the test for 5 days in the morning and in the evening. Drink less water 3-4 hours before the test so as to not dilute the urine. 

Also, the test can be a false-negative if it is damaged or expired. However, the level of the luteinizing hormone (LH) may be high even during the anovulatory cycle.