It is common for pregnant women to experience abdominal pain during various stages of pregnancy. In your 12th week, as your uterus continues to grow and stretch, you may feel discomfort or mild cramping sensations. This is usually normal and can be attributed to the ligaments supporting the uterus stretching and adjusting to accommodate the growing baby. However, if the pain is severe, persistent, accompanied by bleeding or other concerning symptoms, it is important to consult with your healthcare provider immediately as it could indicate a potential issue such as an ectopic pregnancy or miscarriage. It's always best to err on the side of caution and seek medical advice whenever you have concerns about your health during pregnancy.