Quoting Caimma:" Record what time your contractions start. When the contractions are 3 minutes apart from start of one ... [snip!] ... people on this site have been told to wait till. http://www.babies.sutterhealth.org/laboranddelivery/labor/ld_when-hosp.html"
Yes, this is exactly what my midwife told me.
Even if your contractions aren't painful, you will notice the tightening in your abdomen. After I had an epidural, I never had the urge to push. We just timed my pushing with my contractions, which I felt as tightening.