xpost: calling all BBT experts: thermometer question

[Hope4More]

Hi! I need help even though I've been doing BBT since, oh, 2009

I've been using a BBT from CVS - a white one with a pink tip. Worked great through my last cycle, and this cycle it's been wonky (although so has my body!). My last three temps were all EXACTLY 97.45 (which were supposed to be my ovulation temps, so I don't know where that puts me now...). I thought maybe my thermometer was bad, but later in the day gave me a different temp, so it's not STUCK on 97.45.

I went to CVS and bought a new one. It's purple. I thought I'd take my temp on both to see if I get similar readings (not the same, but it should be in the same ballpark, RIGHT?). The old thermometer comes back at 96.78. The new thermometer comes back at 97.33. I cross checked it with a fever thermometer (which is only valid to two tenths, but it would tell me which one was right), and it came back 97.5. soooo... is the old one wonky? But the bigger question is, do I start charting with the new one? I'm already on day 22, no o in sight, although all signs pointed to an O within the last 3 days or today. I think this means my WHOLE chart is going to be off, which wouldn't be that big of a deal if I had normal cycles, but I don't. I go from 25 days to 72... I guess i'm asking what would you do?

[TrennaII]

I wouldn't switch thermometers mid cycle. Just change the batteries in your old one.

It doesn't matter so much whether it's got the exact correct temperature, but whether it catches shifts in temp, right? Whether it's 97.3 degrees or 105 jelly beans, we just need it to say "things changed by 4 units since yesterday."

Keep checking temp with both, and see if the new one and old one shift at the same time, about the same amount. It'd be normal for them to not display the same temp.

[doulamomma]

Originally Posted by TrennaII I wouldn't switch thermometers mid cycle. Just change the batteries in your old one. It doesn't matter so much whether it's got the exact correct temperature, but whether it catches shifts in temp, right? Whether it's 97.3 degrees or 105 jelly beans, we just need it to say "things changed by 4 units since yesterday." Keep checking temp with both, and see if the new one and old one shift at the same time, about the same amount. It'd be normal for them to not display the same temp.

I agree. Just like two scales arent going to weigh you the exact same.

Sent from my droid

[cathplyr]

remember all kinds of things affect bbt like stress or sleep. also remember sometimes you dont have it on the exact same place in your mouth. I put the thermometer on both sides under my tongue so I def. have it positioned correctly at least 1 time. If the reading looks suspicious I take it again. If it still looks suspicious I see what happens the next day or the third day. I also check CM and that usually settles it. some cycles you know which day you ovulated and some cycles your trying to decide on 2 or 3 days. so err on the side of caution. keep using the old one although does it really matter? I only take my temp for a week or so just to confirm ovulation that way I dont get too overwhelmed by the process.