Whether it's a mild stomach ache, sharp pain, or stomach cramps, abdominal pain can have numerous causes. Some of the more common causes include: Indigestion. Constipation. Stomach virus. Menstrual cramps. Irritable bowel syndrome (IBS)
http://www.webmd.com/pain-management/guide/abdominal-pain-causes-treatments
Cramping after the initial stages of pregnancy is called round ligament pain. These cramps may be dull and achy, or a sharp pain that you notice when changing position. This cramping occurs because the muscles under your uterus expand and grow in order to support the weight of your uterus and baby as it grows.
https://www.babiesonline.com/articles/pregnancy/pregnancycramping.asp
Implantation Cramping. In the first few weeks of pregnancy, implantation cramping, oftentimes accompanied by implantation bleeding, occurs when the fertilized egg attaches itself to the uterus. Some women might feel implantation cramping as soon as seven days after they ovulate, while others might not feel cramping at all. Cramping may continue throughout pregnancy as the uterus prepares to carry a baby for nine months. Your uterus is a big organ and as it grows in early pregnancy cramping is not uncommon.
https://www.babiesonline.com/articles/pregnancy/pregnancycramping.asp
Stomach cramps may be generalized, which means they occur throughout the abdomen. Stomach cramps may also be localized in a small area of the belly, such as the lower abdomen or pelvis near the groin, or in the upper abdomen where the stomach is located.
http://www.healthgrades.com/symptoms/stomach-cramps
Sometimes, the stomach cramps and pain are the worst part about the stomach flu. Is there anything you can do to ease this symptom of the norovirus that’s hitting so hard this year? Stomach flu causes inflammation of the lining of the stomach, small intestine, and large intestine.
https://www.decodedscience.org/stomach-flu-cramps-symptoms/27101
Long-term stomach cramping may be continuous or occur periodically and may be due to more serious conditions, such as colorectal cancer. In some cases, stomach cramps may be caused by serious conditions, such as food poisoning or colorectal cancer.
http://www.healthgrades.com/symptoms/stomach-cramps
If your abdominal pain is severe or recurrent or if it is accompanied by any of the following symptoms, contact your health care provider as soon as possible: 1  Fever. 2  Inability to keep food down for more than 2 days. 3  Any signs of dehydration.  Inability to pass stool, especially if you are also 1  vomiting. Painful or unusually frequent urination.
http://www.webmd.com/pain-management/guide/abdominal-pain-causes-treatments
Stomach Flu Symptoms: Cramps and Nausea. Stomach flu causes inflammation of the lining of the stomach, small intestine, and large intestine. Viral gastroenteritis is highly contagious and affects millions of people around the world every year with vomiting, watery diarrhea, headache, fever, chills, and abdominal pain and cramping.
https://www.decodedscience.org/stomach-flu-cramps-symptoms/27101
Just about everybody at one point or another will experience abdominal pain. Most of the causes are not serious and can be readily diagnosed and treated. However, pain can also be a sign of a serious illness. It's important to be able to recognize symptoms that are severe and know when to call a doctor.
http://www.webmd.com/pain-management/guide/abdominal-pain-causes-treatments
Note: When you have the stomach flu, you generally feel pain in more than half of your stomach. If your pain is only in one part of the abdomen (localized pain) it could be a sign of problem with another organ such as your gallbladder or appendix.
https://www.decodedscience.org/stomach-flu-cramps-symptoms/27101
why does stomach feel crampy?
Stomach feels crampy because the muscles under your uterus expand and grow in order to support the weight of your uterus and baby as it grows. The stomach can feel crampy because the muscles under your uterus expand and grow in order to support the weight of your uterus and baby as it grows.