Most women will experience "fake" contractions sometime in their pregnancy not all women, but most. Fake contractions, more commonly known as Braxton Hicks contractions, are real, honest-to-goodness contractions of the uterus. They look real on a uterine contraction monitor. They feel real. But they're not called real. The difference being that they are irregular contractions, and they don't cause your body to go into labor or your cervix to dilate. True labor is contractions with cervical changes.
Usually, you'll start feeling Braxton Hicks contractions sometime in the second trimester, getting more pronounced the farther along you go in pregnancy. They can feel like a tightening of the stomach, as your abdomen (or rather the uterus) gets hard for no reason. You'll know it when you feel it. If you touch the stomach with your hand while one of these contractions is occurring, it feels like a tight drumhead. There is no way to control the contraction. It will usually pass in a few seconds. In the meantime, just breathe your way through it. Or try changing your activity or drinking some water to alleviate the tightness.
Braxton Hicks contractions can be triggered by something as simple as the baby moving or someone merely touching your stomach. Although they are often called practice contractions, they don't actually play a part in dilating or effacing the cervix, like real contractions do.
Typically, Braxton Hicks contractions are not especially painful, but more uncomfortable than anything. These contractions may vary from a few seconds to half a minute, and you can't predict when they will occur. You may have a run of three or four contractions an hour, and then they will just stop for no reason. They might not come back for weeks, or they could come back an hour later. Go figure.
From the Doctor's Perspective...
Since people have different pain thresholds, some women do describe Braxton Hicks as being very painful. When I ask a first-time mother to rate the pain, she may say it's a "10." Because she hasn't experienced labor yet, that pain is indeed a 10 to her. Usually, when that same woman goes into labor, she'll say that it hurts worse than Braxton Hicks, ergo the pain is now off the charts. Be aware that other factors may contribute to the intensity of your perception of "painful" contractions, anxiety being one of those conditions. Try to rest and minimize the stress in your life.
Having said that, the caveat is to always consult your care provider if you're in extreme pain. The pain could be coming from another source, like the bladder, yet feel as if it's in the same location as the uterus. Or it could be coming from a pulled muscle or a gastrointestinal problem and needs to be investigated further. Don't live with unnecessary pain. Make sure that nothing else is wrong.
In comparison to Braxton Hicks contractions, real contractions are regular in duration and regular in their interval spacing. As labor progresses, they get more intense and last longer. For example, they may start off lasting a few seconds and occurring 10 minutes apart, but every hour they get closer and closer together and last longer. On average, a real contraction lasts from 30 seconds to one minute each. Typically, you'll start off with four to six contractions in one hour. When you have four to six contractions for two hours in a row, it's time to call the doctor. Chances are good that you're in labor!
Real contractions can be anything from a dull ache and a tightening of the uterus (à la Braxton Hicks) to all-out, excruciating, gut-wrenching, eye-popping pain. Believe me when I say that you'll know it's the real thing when you experience them.
When contractions start, you should time them with a stopwatch to see how long they last. Then time them again to see how far apart they are. The doctors, nurses, and hospital personnel will all ask you these questions. "How far apart are they? How long do they last?" Get your partner to keep a chart of the contractions. This will often help the doctor determine over the phone if you need to get to a hospital, and if you're close to delivery. Nobody wants you to have that baby in the car, least of all your partner.
Be prepared for the contractions to change quickly, meaning that they can go from easy and manageable pain to over-the-top and unremitting, wrenching pain in what seems like an instant. When this happens, it means that the baby is progressing down the birth canal.