At 33 weeks of pregnancy, the belly resembles a menstrual period, with bouts of tightness and pain, to mention a concept known as false contractions. In the second trimester, due to the rhythmical nature of the uterus itself, there is a certain amount of uterine muscles that experience a spontaneous process of tension. If this tension is not too regular and does not last for a long time, this tense, painful, hardening uterine phenomenon is called a pseudo-contraction. This is a physiological reaction of most of the uterus itself and should not be a big problem, so there is no need to worry too much about it. For most pregnant women, you should pay attention to whether the pain lasts for a long time or not, and whether it lasts regularly. If it lasts longer and is more regular, it may be a real contraction. Once these contractions occur, it is advisable to go to the hospital in time, because the fetus itself is not mature at this time, and the contractions should be suppressed to allow the fetus to grow in the womb without worry.