This is a sample slow rise chart
This month I experienced something totally different - a BBT pattern change. If you don't know what I'm talking about, many women chart their basal body temperatures to chart ovulation (see this post). In my past two cycles I'd had a very traditional chart (some say ideal, but who knows what ideal is) -- where ovulation causes a dramatic temperature spike (they say anywhere from about .5 degrees to 1 degree) immediately after ovulation. But this month, having known I ovulated (per my fertility monitor and other symptoms) I did not get the same dramatic shift. (Note: this is where charting month-to-month is nice, because you have charts to compare against)
Instead, I got an upward shift that looked like a stair case, up .2 degrees, flat a day, up another .2 degrees, flat a day, etc. So I started googling "BBT patterns and chart types" thinking perhaps something was wrong. Thankfully there were one or two sites that helped explain to me the differences in chart types...all of which are considered normal. They are:
A Sloping Rise: Where temperatures very slowly increase (.2 - .3 degrees each day) until they hit a plateau and stay there until they fall at the end of the luteal phase. These charts often look like a sloping hill.
A Slow Rise: What I had. The thermal shift isn't apparent until a few days after ovulation. Like a sloping rise, the temperatures increase gradually, but over a longer period of time (usually taking 4-6 days to hit the plateau).
A Fallback Rise: After ovulation, your temperature shoots up dramatically, but on the second day it dips dramatically downward, often past your coverline. Then on the third day it shoots back up again to the plateau.
A Staircase Rise: The temperature rises a few, drops a few, then rises a few more, then drops a few, then rises even more, then drops a few, etc. For example, up .3, down .2, up .4, down .2, up .3, down .1, etc. To me, these charts look like mountains on a diagonal.
I haven't found very concrete information yet, on what would cause a chart to shift patterns, but seeing as how it's still considered normal, I'm not too worried. The nice part is I'm very good at recognizing the BBT chart type of others now, so it has been a fun learning experience.
Do you know what BBT chart type you have? Has it always been the same, or has it shifted at times to other patterns? What chart type did you have when you got a BFP? I'd love to hear from you!