Physicians that could answer questions such as these include your OBGYN, or even a primary care physician
such as a family doctor
. There is a lot of variation in the development of the pregnant abdomen. A lot of it depends on the size of the women's abdomen to begin with. Women that are particularly thin will experience a firm belly sooner than those that start off with a larger abdomen. This is because the firmness of it depends on how much fat is underneath the skin. In general, most women begin to experience what they describe as a full and firm abdomen by 20 weeks, or close to the end of the 2nd trimester. I would not worry
much if your belly doesn't feel like you think it is supposed to. Frequent visits with your OBGYN will insure that you are progressing as you are supposed to. I suggest that you write down every question that comes to mind between now and your next visit with your OBGYN. These are the types of question that your physician should be able to answer for you. Your body is going to go through many more changes between now and the time you have the baby. Good luck.