The most rigorous method of pregnancy testing is to perform two tests, which can achieve an accuracy rate of 100%. The general situation is to perform the first pregnancy test after 21-25 days of breeding, and to repeat the test within 35-45 days of breeding.The purpose is because in the early pregnancy of the pig (20 days of breeding), the problem of hidden abortion is prone to occur. The gestational sac is absorbed by the uterus and does not show the symptoms of miscarriage. Therefore, the second pregnancy must be performed in about 40 days. In order to improve its accuracy, if the sows are miscarried for forty days after breeding, there will be symptoms of miscarriage. We can observe in time that if the veterinary B ultrasound scanner test is pregnant, we can conclude that the sow is pregnant.