What makes a chart triphasic?

It's tri-phasic if there are two noticeable increases in temp - another one in addition to your usual increase. The second one usually starts a good number of days after the first, usually closer to the time you'd test positive. This generally keeps at this elevated temp for the duration of your pregnancy, but can drop slightly too. It doesn't reflect on the health of your pregnancy, but a drop down to pre-ovulation temps can be indicative of a miscarriage. This relates to a triphasic chart in pregnancy.

A triphasic chart wil show the original elevation in temps after ovulation and then a week or more later the temp will rise to a third level and stay elevated. This is a good indicator of pregnancy but not a sure thing. Also not ALL pregnancy charts will show the triphasic pattern. See the chart galleries at ovusoft.com for some examples.

"A triphasic chart shows three levels of temperatures: pre-ovulation, post-ovulation, and then a second rise around 7-10 days after ovulation. Some women with charts that show this pattern turn out to be pregnant. But many do not"

http://www.fertilityfriend.com/Faqs/Triphasic-Patt...

http://www.fertilityfriend.com/Faqs/Triphasic-char...