At 16 weeks pregnant, pain in the pubic bone may be normal or it may be due to calcium deficiency or other reasons. 1. Normal: A very small number of pregnant women may experience pain at the pubic symphysis due to an enlarged uterus at 16 weeks of pregnancy. This is normal and most of them will be relieved naturally after delivery. 2. Calcium Deficiency: Pain in the pubic bone at 16 weeks of pregnancy may be caused by calcium deficiency. The demand for calcium increases after pregnancy, and if calcium intake is insufficient, symptoms of calcium deficiency, such as pubic bone pain and leg cramps, will easily occur. Pregnant women should pay attention to regular checkups during pregnancy, and if abdominal pain or abnormal vaginal bleeding occurs at any time, please consult the hospital in a timely manner for active treatment.