For those of you with visions of either giving birth in your car or making repeated "false alarm" trips to the hospital or birth center, this checklist is for you.

To begin with, forget about TV portrayals of labor, where pregnant women suddenly look startled, clutch their bellies, and gasp, "This is it!"

You'll have time to figure things out. The average labor lasts nine hours in first-time mothers and six-and-a-half in women laboring again -- and that's from the onset of regular, painful contractions, occurring five to three minutes apart. Most women have several, if not many, additional hours from the time the first vague twinges begin and this pattern setting in.

While you're waiting to see what develops, here are seven guidelines that will help you distinguish between prelabor contractions and the real McCoy.

1. How do the contractions feel? Labor contractions are felt low in the groin or in the lower back. They may radiate from front to back or back to front or down your legs. They are dull and crampy like menstrual or gas cramps. Prelabor contractions, which you may have been experiencing for months, feel like a tightening across your belly or like the baby suddenly stretched in all directions.