Hi Abdominal muscles do become lax with stretching of pregnancy. Most often there is some extra fat deposited in the abdominal wall by the end of pregnancy. This is the most common reason for abdomen sticking out. since you are saying that you are noticing it by the end of the day, please consult surgeon and make sure there is no abdominal wall hernia. Once this is ruled out, consult gym trainer/physiotherapist and start abdominal exercises and aerobics. At the same time discuss with nutritionist regarding the right type of food you need to take. You will start noticing change only after one month. So have patience and don t give up. I hope I have answered to your satisfaction. If you have any further queries feel free to ask me through health care magic.