Failure to detect a strong positive with ovulation test paper may be caused by the patient drinking a lot of water before the test, inappropriate time for the test, poor follicular development and other reasons. 1. Drinking a lot of water before the test: If the patient drinks a lot of water before the test, it will dilute the luteinizing hormone in the urine, leading to the phenomenon of not being able to detect a strong positive on the ovulation test paper. 2. Test time is not appropriate: the patient may test time is not appropriate, so the ovulation test paper can not detect strong positive, the patient should be in the ovulation two days before the beginning of the test, but also can be appropriate to increase the number of tests, shorten the test time, so as not to miss the emergence of the LH peak. 3. Follicular dysplasia: patients with follicular dysplasia, follicular atrophy, hypoplasia, there will also be the phenomenon of ovulation test paper can not detect strong positive, you can go to the hospital for ultrasound to diagnose the development of follicles. If the patient fails to detect strong positive with ovulation test paper for several times, she can go to the hospital for examination, and the test can be conducted under the guidance of the doctor.