Last menstrual period April 25, the earliest after intercourse 7-10 days after the pregnancy can be measured, commonly used detection methods: early pregnancy test strips, blood HCG, ultrasound test these kinds of. 1. Early pregnancy test strips: the most simple and convenient way, generally 7-10 days after intercourse can be detected, the best urine test is morning urine, there is also because of the short time of coitus false negative situation, so it is best to test 2 weeks after coitus, and if necessary, retesting. 2. Blood HCG: a more accurate way of checking, its time to find out the pregnancy is generally earlier than the early pregnancy test strip, such as the results of the test more than the reference range suggests that the pregnancy, the specific should also be based on the ultrasound to determine whether it is a normal pregnancy. 3. Ultrasound: the timing of ultrasound pregnancy check is a little later, generally 35 days after menopause or blood HCG reaches 2000 or more to see the gestational sac in the uterine cavity. Delayed menstruation should be considered whether there is a possibility of pregnancy, but not necessarily pregnant, when there is delayed menstruation, such as want to confirm the diagnosis of pregnancy after the hospital.