At 40 days of pregnancy, the gestational sac is about one centimeter. At this point the organs of the fetus begin to differentiate, but it is not always possible to see the fetal heart and buds, mainly because the pregnancy is relatively short. After 8 weeks of pregnancy, the fetal heart and buds can be seen on an ultrasound. If the fetal heart is still not visible at this time, it is possible that the embryo has stopped developing. In early pregnancy, you must relax, do not overstress, and ensure sufficient sleep, which is conducive to the development of the embryo. Early pregnancy nutrition must be balanced, try to do not partiality, not picky about food, meat and vegetables with, do eat more meals. You can eat some fresh vegetables and fruits, lean meat, eggs and milk in moderation. Diet to do both easy to digest, but also nutritious. Avoid spicy, stimulating and cold foods during pregnancy to avoid discomfort.