During pregnancy, it is common to experience symptoms like excessive flatulence, constipation, abdominal pain, and changes in the pelvic area. Hormonal changes can lead to increased gas production and slowed digestion, causing flatulence and constipation respectively. To alleviate these symptoms, try eating smaller meals more frequently, staying hydrated, consuming fiber-rich foods like fruits and vegetables, and engaging in regular physical activity (with your doctor's approval). As for the sensation of something opening in your pelvis, it could be due to the relaxation of ligaments supporting the pelvic joints as your body prepares for childbirth. This is known as pelvic girdle pain or symphysis pubis dysfunction (SPD), which is common but can vary in severity from person to person. If you're concerned about the intensity or frequency of the pain or any other symptoms you're experiencing, it's always best to consult with your healthcare provider for personalized advice and reassurance.