Apart from the normal reason of pregnancy that makes the female gender have a protruding stomach there are some other reasons that one need to be very conscious about when you begin to have an increasing stomach.
Sometimes it might be as a result of taking in excess calories.
You may be having some hormonal changes.
You may be regaining water weight.
Your digestive system might be getting off kilter.
It may be as a result of your delay in visiting the doctor about the pains you feel in your abdomen.
It may be as a result of your over feeding.
You might have an expansion in your stomach if you are bloated.
When your movement is restricted, you probably do not allow so much movement, then your stomach might begin to get bigger.
There is a possibility that your stomach might increase through excessive stress.
Increase in age may cause the increasing of a person's stomach.
This are some ideas I obtained while reading through some things. Thank you for reading, it's your baby in the womb 