The time of pregnancy is not the same as the time of conception, about which you must not be confused, if the ultrasound shows that the pregnancy is 6 weeks, then the actual time of conception should be about 4 weeks. We usually calculate the number of days or weeks of pregnancy according to the time of the last menstrual period, but this method of calculating the number of weeks of pregnancy is usually longer than the ultrasound examination. The entire pregnancy period is 10 months, or 280 days, and through ultrasound we can not only deduce the actual time of conception, but at the same time, the expected date of delivery. The 6 weeks of pregnancy belongs to the early stage of pregnancy, this period of time the fetus is quite unstable, pregnant mothers must pay attention to strengthen the nutrition during this period, and regular maternity checkups. Fetal babies in this period, the head, face organs have begun to slowly differentiate, the primary heart and kidneys, has been shaped, and the fetal heart rate is relatively high, equivalent to about twice that of our adults, in the ultrasound examination, you can clearly see the fetal sac. Expectant mothers in early pregnancy, the development of the fetus is still immature, a little negligence may lead to miscarriage, so we must take care of their own bodies, pay more attention to rest, do not do physical work, so as not to cause adverse effects on the fetus, resulting in a major disaster.