There are many reasons for infertility, involving factors from the male, the female, or both. The specific timing for testing cannot be generalized and should be determined based on the test required. For male factors, if a semen analysis is needed, it is best to abstain from ejaculation for two to seven days and conduct the test in the morning. If testing involves blood work for six sexual hormones, it should be done in the morning on an empty stomach. A prostate examination requires urine retention before the test. For female factors causing infertility, blood tests should also be done in the morning on an empty stomach. Hysterosalpingography should be scheduled to avoid the menstrual period, ideally two to seven days after the period ends. Consult a professional physician for other specific tests.