Tightness and firmness at 34 weeks is normal if it is occasional; if it is constant, it may be due to preterm labor.
Tightness and firmness of the stomach is mostly due to contractions during pregnancy, and you need to judge whether they are true contractions or false contractions based on the duration, frequency and interval of the contractions.
False contractions are usually not regular, do not last very long, the interval is not regular, usually with the increase of pregnancy weeks, once in a while is no effect.
True contractions will gradually increase in duration, shorten in interval, and show regular tightness and hardness, accompanied by abdominal pain. If contractions occur, it is necessary to consider the week of pregnancy and the condition of the fetus to see whether it is a sign of labor or preterm labor.
Therefore, it is normal to experience occasional tightening and hardening of the stomach at 34 weeks, but if it occurs frequently, then you need to be vigilant about whether there is preterm labor, and you need to consult a doctor in a timely manner.