Your belly keeps getting bigger, but it’s worth noting that belly size varies from one woman to another.
The size of your belly depends on the child's growth, body structure and body shape, length and weight, possible previous pregnancies as well as how much fluid your body stores. Therefore, it is not a good idea to compare the size of your belly with someone else, nor with your own, if you have been pregnant before. The large belly causes it to sometimes bump into ribs and lungs, which means that you may feel some pain below the lungs and at the back of the lumbar spine.
The uterus and the child are growing at such a fast rate that it pushes and draws into the ligaments that the uterus "rests in." In the lumbar spine, joints and muscles are affected by the uterus and the baby. Listen to signals coming from your body, think of your posture, and use your abdominal muscles to keep your back straight.