It is not uncommon to experience stiffness or tightness in the belly during the later stages of pregnancy. This can be caused by a variety of factors, including Braxton Hicks contractions, which are practice contractions that help prepare your body for labor. These contractions are usually irregular and do not increase in intensity or frequency. However, if you notice any changes in your baby's movements, severe pain, or regular contractions that become more intense and closer together, it is important to contact your healthcare provider as these could be signs of preterm labor. Additionally, if you have any concerns about the stiffness or any other symptoms you are experiencing, it is always best to consult with your healthcare provider for personalized advice and reassurance.