If the patient has normal menstrual periods and ovulates regularly, pregnancy can be detected between 3-4 weeks of pregnancy by checking the blood chorionic gonadotropin or doing a urine pregnancy test, as it takes about 16 days for the follicle to develop. After the follicle has been released, it takes about a week for the sperm and egg to meet and form a fertilized egg, and for the egg to implant itself in the uterus. Within 1-2 days of the fertilized egg’s implantation, the patient’s blood chorionic gonadotropin and progesterone levels rise rapidly, so pregnancy can be detected by checking the blood chorionic gonadotropin. Within 3-5 days after pregnancy is detected by blood tests, a urine pregnancy test can be performed to determine if the patient is pregnant. However, the blood and urine tests can only determine whether the patient is pregnant or not, but cannot determine whether the patient is pregnant inside or outside the uterus, and ultrasound is needed to make the final judgment.