As the big day approaches, you may wonder whether you'll know when you're in labor. Don't worry: A woman's body almost always gives her the signals she needs and the inner wisdom to recognize them.

Signs Labor is Near

There are two main indicators that you'll start labor within a day or two.

1. Rupture of membranes (amniotic sac). You may have also heard this called having your water break. The amount of clear amniotic fluid that escapes from the sac and flows out of the vagina differs from woman to woman. For some it's just a little trickle; for others it can be a gush. Surprisingly, this precursor to labor is a first symptom in fewer than 25 percent of women; it may actually occur during labor instead of before it. But when it happens prior to labor, there's a good chance that labor will start within 24 hours. If your water breaks, notify your doctor or midwife immediately. Note the time it breaks, the color and amount of fluid, and whether there is any foul odor. Report all of this information to your health care provider.

2. Bloody show. A day or two before contractions begin, you may notice a pinkish or blood-streaked mucus discharge. This "bloody show" is actually the mucus plug that has sealed the cervix during pregnancy. Not all women notice this discharge, and some women begin contractions before the mucus plug is discharged. Also, keep in mind that the bloody show is not the same as the brownish, bloody discharge you might experience after a vaginal exam at a prenatal appointment, which is no cause for concern.

Early signs of labor: Contractions

The big tip-off that you're in labor is the start of regular uterine contractions. At first, these early contractions feel like menstrual cramps or a low backache that comes and goes at 20- to 30-minute intervals. Gradually, the aching or cramping becomes stronger and lasts longer. The contractions also get more frequent, until they come every three to five minutes. To time your contractions, write down the exact time each one begins and how long it lasts.

Real Labor or False Labor?

True Labor

False Labor

Contractions are regular and follow a predictable pattern (such as every eight minutes).

Contractions are irregular and unpredictable, occurring, for example, in intervals of ten minutes, then six minutes, two minutes, eight minutes, etc.

You experience three types of progression: Contractions become a) progressively closer, b) progressively longer, and c) progressively stronger.

No progression is seen over time.

Each contraction is felt starting in the low back and then radiating around to the front, low in the groin.

Contractions are felt as a generalized abdominal tightening.

A change in activity or position will not slow down or stop contractions.

A change in activity or position may cause contractions to slow down or stop.

There may be bloody show.

There is usually no bloody show.

Membranes may rupture.

Membranes will not rupture.

Your doctor or midwife will notice cervical changes, such as ripening (softening), effacement (thinning), or dilation.

No cervical changes occur.

Making the Call

You should call your health care provider if you think you are in labor. Have your notes with you when you make the call so you can give accurate information about your symptoms. Don't be afraid to call at any time, day or night. Your provider knows that labor doesn't always start between the hours of nine and five, and when physicians or midwives are on call, they expect the phone to ring -at any hour.

Also, keep in mind that you may not need to go to the hospital immediately. In fact, if this is your first baby, most physicians or midwives suggest you stay in the comfort of your home until the contractions have reached five-minute intervals. If you've had a previous labor and birth, you may be asked to come to the hospital sooner, because your labor may move along more quickly.

Realizing you're in labor will bring a mixture of feelings, including excitement, disbelief, and apprehension. Try to stay calm and focused. Arrange to have your partner or a friend with you to help you record your symptoms, keep you company, and get you to the hospital when the time comes. Above all, know that you can do the job that lies ahead: bringing your baby into the world!