Is a human chorionic gonadotropin <20 units pregnant. First of all, it is certain that a human chorionic gonadotropin <20 units is not pregnant. However, if you have intercourse after 8 days during ovulation, you can test for it, but if it is less than 8 days or shorter, you cannot test for it. The second is that the unit of testing differs from hospital to hospital, but each hospital is less than 20 units, are not pregnant state, if after 10 days of intercourse human chorionic gonadotropin < 20 units, is confirmed not pregnant.