I can't remember who, but someone said they take their temp twice (orally and vaginally, I think?). I'm wondering how you can have 2 simultaneous charts in FF, or how you keep track of the 2 sets of temps.

BFP#1 - 11/13/11, Natural MC - 12/24/11 at 12 weeks
BFP#2 - 10/2/12, Please be our rainbow.

Re: How do you double chart or back up your temps?
I temp both.
You can't have two FF charts, it won't let you create another chart if you already have an account (I even tried with different emails, but it recognized my up address)
I started after last cycles really erratic temps. I wanted to know if it was my temping style or my body. I created a second chart on TCOYF site. It's not nearly as user friendly, doesnt have analysis data like the FF membership, and even told me my vaby dabcing 2 days after ovulation was my best chance of conceiving ( versus the bd before...) In the morning when I temp I write my vaginal temp in the notes on FF. every few days or so I'll log them in on the TCOYF site, it soley for seeing how reliable my oral temps are. It's helped me decide which temps on FF are worthy of discarding and which ones are valid jumps.
FWIW, it landed up being that my jumpy temps last cycle were my body as my two charts now are on a similar curve pattern. It's made me feel better about my loss last cycle by saying my hormones were screwy and not ideal for making a baby.
BFP#1 10/1/2011. Our perfect little girl, Her heart stopped @ 12w1d. D&E 11/23/11
BFP#2 3/13/12 Weird CP/Possible EP @ 6w0d
BFP#3 5/28/12 CP @ 5w0d
BFP/WTF#4 10/26/12 CP
BFP#5 12/10/12 EDD 8/23/2013
BFP#1 - 11/13/11, Natural MC - 12/24/11 at 12 weeks
BFP#2 - 10/2/12, Please be our rainbow.
Yeah, listen to Katharine ... She is wise with the charting!
We lost our first (EDD 07/23/12) after finding out at 12 weeks there was no longer a heartbeat. Our rainbow was born 05/22/13 and was worth all we went through.
“So can you understand? Why I want a daughter while I’m still young? I wanna hold her hand and show her some beauty before all this damage is done. But if it’s too much to ask, it’s too much to ask … Then send me a son.” – Arcade Fire
One final word, I've notice my oral temps to be very susceptible to time change or lack of sleep, where vaginal temps you have a bit more leeway. For the most part, I haven't noticed any difference when I temp consistent time and and good sleep. My vaginal temps do run about an average of .5 to .7 degrees higher than my mouth, which I also note in FF notes. For instance, if my oral temp is 97.3 and my vaginal temp is 97.8, in the notes I'll write "97.8, +.5" then when you look at "all data" on FF you can quickly tell if there's a big variation in the degrees difference.
BFP#1 10/1/2011. Our perfect little girl, Her heart stopped @ 12w1d. D&E 11/23/11
BFP#2 3/13/12 Weird CP/Possible EP @ 6w0d
BFP#3 5/28/12 CP @ 5w0d
BFP/WTF#4 10/26/12 CP
BFP#5 12/10/12 EDD 8/23/2013
BFP#1 - 11/13/11, Natural MC - 12/24/11 at 12 weeks
BFP#2 - 10/2/12, Please be our rainbow.