The first ultrasound after pregnancy is recommended to be done around 6~7 weeks of pregnancy. The main purpose of the first ultrasound is to rule out ectopic pregnancy and also to monitor the fetal heartbeat and fetal buds. The pregnancy is counted from the first day of the last menstrual period, and ultrasound examination at 6~7 weeks of pregnancy can usually identify the fetal sac and its position, if the fetal sac is inside the uterine cavity it is considered an intrauterine pregnancy, and if it is in the cervix or fallopian tube it is considered an ectopic pregnancy. Ultrasound is usually needed 6 to 8 times throughout the pregnancy. The first ultrasound is at 6-7 weeks of pregnancy, the second is at 11-13 weeks of pregnancy, mainly to measure the NT value; the third is at 22-24 weeks of pregnancy, mainly to screen for fetal anomalies; the fourth is at about 26 weeks of pregnancy, to review the screening for anomalies. The 5th time is around 32 weeks of pregnancy, the 6th time is around 37 weeks of pregnancy, and the 7th time is around 40 weeks of pregnancy. The last 3 times are for determining the size of the fetus, the amount of amniotic fluid, the position of the fetus, and the umbilical blood flow. You can consult your obstetrician and gynecologist at the hospital and schedule your ultrasound according to your actual pregnancy week under the doctor’s guidance.