For women who usually have a particularly regular menstrual cycle, pregnancy can usually be diagnosed by checking blood HCG about 1 day after menopause. Because the HCG in the blood has risen by this time, it is possible to determine pregnancy by the exact value of the HCG. If a woman uses pregnancy tests or pregnancy sticks, the test may need to be done more than 5 days after the period to be accurate. This is because HCG in the urine appears later than HCG in the blood, and a false (-) is likely to occur if the test is taken too early. However, if a woman wants to check ultrasound to determine pregnancy, it is usually more than 10 days after her period has been pushed back.