In true labour, the contractions are regular, starting at 10 minutes and then slowly shortening to 5-6 minutes apart, with the duration of the contractions gradually increasing. The contractions can last up to 1 minute, and the forced pressure will spread to the pelvis and even the legs, and you will feel the sensation of the fetal head dropping, the pressure, or the feeling of stooling.
The first thing that happens before labour is pseudo-contractions, which tend to occur more often at night, at irregular times, and often ease up during the day, or after rest. Pregnant women nearing labour should be aware of these phenomena.