After the egg is discharged ovulation test paper from strong positive into weak positive, with the time delay into negative, ovulation test paper is to check the urine luteinizing hormone, after the egg is discharged luteinizing hormone gradually reduced, easy to cause ovulation test paper into weak positive or negative. In the ovulation period need to regularly use ovulation test paper to see whether the follicle is discharged, after ovulation need to timely intercourse, in the ovulation before and after 1-2 days of intercourse with the highest chance of pregnancy. The use of ovulation test paper check has a certain error, drink water after the urine is diluted will cause the urine luteinizing hormone concentration is reduced, easy to cause negative, it is best to go to the hospital for ultrasound follicle check is more accurate, through the ultrasound can determine whether the follicle development is normal, but also to determine whether the ovulation, ovulation is in the next menstrual period of 14 days before the onset of the next day or so.