How long it takes to detect pregnancy depends on the test method, such as: early pregnancy test paper can be delayed for about 7 days after menstruation, blood HCG can be detected about one week after intercourse, and ultrasound can be detected in 5-7 days after menstruation.
Early pregnancy test paper is more accurate to test time in the menstrual delay of about 7 days, the earliest can be measured in 2 weeks after intercourse. Blood HCG is one of the earliest tests that can detect pregnancy, usually about 1 week after intercourse. ultrasound is relatively late, usually 5-7 days after menstruation can see the echo of the gestational sac.
The above test times are for regular and normal menstruation, irregular menstruation needs to be tested after the delay of the last menstruation intermittently. If you need to diagnose pregnancy accurately, you should go to the hospital in time and under the guidance of your doctor.