Thyroid Basics Explained

I just had blood drawn this morning in order to have thyroid (and liver) markers tested, as part of my high-SHBG / low-Free-T connundrum, recently detailed here:

After reading the Thyroid sticky, I took my waking temperature this morning and it was 97.2. So that’s low. I got a hold of some Iodoral from a store today and took my first 25 mg dose, and am planning to do 50 mg/day as per KSman’s advice.

However, just now I got home and took my 5:30 pm temperature and it’s 95.9 (!) WTF?! Can that be right, or is my 8-dollar Walgreens digital thermometer just not to be trusted? What would this mean, if true?

Thanks.