BBT Mercury Thermometre and room temperature

This is a question I also posted in the OPK thread, wondering what people's experience has been this winter?

Is it possible that very cold room temperature has affected the quickness of responce on the BBT thermometre to reach my maximum BBT? I'm not being very clear.. but lately, Perth has been very cold, and my thermemtre was left out of it's case by the bed, in about a 5 degree C room. I put the thermemtre in my mouth for the usual time that I always do (about 3-4 minutes). But, the thermometre feels very cold on the outside of the glass... so do I need to leave it in my mouth for longer for it to "warm up" ? If this is the case, this may explain my low-ish temperatures, after my "near positive" OPK on CD14 (I have recorded it as a positive as it was the darkest the line was compared with other days).

Yep I would leave it in your mouth longer in winter. Even with my digi thermometer I notice it has to stay in longer during the colder weather.

.... Mystery SOLVED!!!

I was wondering why my BBT was so low when I should have already ovulated.. normally it jumps up to 36.6 and above.

So to test it, this morning I drove my DH to the airport at 6am, then took my dog for a half hour walk, then spoke to my dog while getting dressed, then took my temperature... after 5 minutes it was 36.05 !!!!!! So I'm concluding that my thermometre is most definately faulty !!!

How frustrating, all those temps now I can assume are wrong. But at least that might mean I ovulated friday or saturday when I got some BDing in !