Ovulation test paper from two dark red lines into a dark and light when intercourse, can be detected under the guidance of the doctor. Ovulation test paper is through the detection of ovulation luteinizing hormone levels to determine the method of ovulation, can be tested under the guidance of a doctor, when the test paper test prompts two deep red lines, indicating that the follicle is mature and the luteinizing hormone level peaked, usually in about 24 hours ovulation, that is, when the test paper becomes one dark and one light, at this time you can have intercourse in order to increase the chances of conception. Ovulation test paper to detect ovulation will be affected by factors such as drinking water, environment and other factors will appear false positive results or false negative results, so for women with fertility requirements can be under the guidance of the doctor through the ultrasound test follicle development to guide coitus, relatively speaking, the accuracy will be higher.