Braxton Hicks contractions, which can begin at any time during your pregnancy, but are usually not felt, especially in a first pregnancy, until about five months, if they are felt at all, are often localized (I always had them high and across the front, but never felt them all the way around from back to front as I did during actual labor) and not necessarily painful, although they do sometimes cause varying degrees of discomfort, especially toward the last few weeks of pregnancy. Unlike real labor contractions though, they tend to be sporadic in nature, and even though they may last for hours at a time, and be consistent in their intervals, (during my first pregnancy, where my son was three weeks late and they told me on Wednesday afternoon that they would perform a c-section on Monday if I didn't go into labor over the weekend, I had them at intervals of between seven and ten minutes apart for the last four days of my pregnancy, which caused my husband and I to make several trips to labor and delivery that weekend, only to be sent home.) they don't continue to grow closer together, and they don't usually continue to increase on the pain scale.
Because of their tendency in the later stages of pregnancy, to become more and more frequent, and in the very last weeks of pregnancy to increase in their level of discomfort, Braxton Hicks Contractions tend to be mistaken for real labor, which is where the term False Labor comes from.
Real labor can be distinguished by the a fore mentioned tendency to grow increasingly longer, closer together in frequency and more painful.You may also notice that you have lost your mucus plug, or had what is called a bloody show, which indicates that your cervix is thinning and you are beginning to dilate, and you might also notice increased pressure in your pelvic area, a feeling like maybe the baby is pushing down on your pelvic wall, you might also suddenly realize that you have a persistent lower back ache, that just will not go away. All of these are signs of true labor. Hope that this helps.