Below is a more detailed list of physical changes a woman's body goes through when labor during pregnancy begins.
Many women will say they have a lightening. This is where the baby has shifted positions and is in place to make his or her move down the birthing canal. This can happen right before birth or even a few weeks prior to. Many women find that they have to go to the restroom more often to urinate.
There will also be a passing of the mucus plug. Throughout the entire pregnancy a mucous plug builds up where the cervix is. As the cervix dilates, the mucous is then released through the vagina. It can be clear, pink or even somewhat bloody. Once the mucous plug has been released, labor can start almost immediately or one to two weeks after.
The bag of water may break which means contractions will start soon thereafter.
When a woman starts contractions, her abdomen will be very stiff or hard. When she is in-between contractions, her abdomen will be softer or more supple. The intensity of the contractions will vary from one woman to another or with each pregnancy. Contractions generally begin with an uneasiness or a pain in the lower back or lower abdomen area as well and there is a feeling of pressure in the pelvis area. As the woman dilates more and gets further along in labor, the contractions will get stronger. If it is a false labor during pregnancy that she is going through the contractions will not be consistent or get stronger. Keep in mind contractions do not go away if you change your position, it doesn't matter what way you are lying, standing or sitting, the contraction will still be there.
Many women find that day may go through false labor also known as Braxton Hicks contractions. These types of contractions are completely common and can start as early as the second trimester but it is more common in the pregnancy's third trimester. Think of it as your body's way of getting ready for true labor. False contractions may sometimes ease up if you change the way you are sitting or the way you're standing. They also do not change in their frequency or intensity.
When it is true labor during pregnancy the contractions will stay no matter what position she's in. True labor usually starts in the lower back and progresses around to the lower abdomen. With false labor the contractions are usually felt in the front of the abdomen or the pelvic area. If you are in doubt whether or not you're in labor then you need to talk with or see your doctor. Your doctor can check to see if you’re dilated and if labor is truly in progress.