If you have intercourse when you are not ovulating, you can usually get a blood test at about 10 days, but there are individual differences. There is also a possibility of pregnancy when intercourse does not occur during ovulation. Generally, a blood test for HCG (human chorionic gonadotropin) levels is conducted about 10 days after intercourse to confirm pregnancy, but the chances of conception will be reduced when intercourse does not occur during ovulation, and it is recommended that women who wish to have children should have intercourse during ovulation in order to increase the chances of conception. Women of childbearing age can, under the guidance of a doctor, use the calendar method or ultrasound to monitor follicular development to predict ovulation and have intercourse during ovulation to increase the chances of conception. The earliest time for confirming pregnancy is to take a blood test of HCG about 10 days after intercourse, and ultrasound can be performed about 40 days after the menopause to determine whether there is an intrauterine pregnancy.