A pregnant woman’s stomach bulging with a bag is often caused by the baby’s daily life, i.e., the baby stretches its arms and legs, or rotates and flips, which is what is known as fetal movement in daily life. At around 18 weeks of pregnancy, most pregnant women will feel the fetus move. In the case of women who are in labor, fetal movement may be felt as early as around 16 weeks. As the baby grows up, its daily activities are increasing and the space inside the uterine cavity is limited, so it is easy to touch the wall of the uterus. If the baby moves more, the wall of the uterus is deformed, and the pregnant woman’s stomach will bulge a bag at this time. In late pregnancy, fetal movement is usually 3-5 times per hour, and regular, rhythmic, not much change, pregnant women will not have obvious discomfort. At the same time movement, posture, emotions, strong sound, bright light and touch the abdomen and other circumstances, can cause changes in fetal movement. If the fetal movement is particularly frequent, or the fetal movement is obviously reduced and the amplitude is weakened, it indicates that there may be acute intrauterine distress, and fetal 3D ultrasound and fetal heart monitoring should be performed to make a clear diagnosis. In addition, because fetal movement and contraction will affect each other, contraction can stimulate the fetus to appear fetal movement, and fetal movement can also stimulate the wall of the uterus to cause slight uterine contraction. The sensations and symptoms of contractions and fetal movements in late pregnancy are similar to some extent, and pregnant women are advised to make a good distinction between contractions and fetal movements. Fetal movements are intermittent and are felt in the same position as fetal movements. Contractions will be hardening throughout the uterus and even the urge to urinate or poop. If you are unable to distinguish between them, you can go to the hospital and see an obstetrician to make a judgment.