A triphasic chart is one which shows three levels of temperature. The lower pre-O range, the higher range or thermal shift after O and then a third higher range again usually 7 - 10 days after ovulation.

Folklore says it is supposed to be a good sign of pregnancy but I've been doing a LOT of reading and whilst it CAN be a good sign, it is no more a good sign than an implantation dip or implantation spotting etc which are all retrospective signs anyway. In other words a triphasic chart, implantation dip or implantation spotting are not certain signs of pregnancy and you can still BE pregnant even if you don't have any of them.

Lisa
PS. AF still hasn't started. My cramping isn't as bad and so far there has been no more blood on fingertips when checking CP and CM either.