I would be extremely surprised if you had no other sx given those very low temps. The sx are pretty wide ranging:
Recently I've found out that the alternative allergy guru in our area has found that there is a high degree of correlation between low thyroid function and his allergy patients. Both DS and I have low temps and some sx other than food intolerances. Both of us show low free T3 and high reverse T3. (These tests are not usually run)
I've been intensively researching the thyroid lately. I have concluded that lab numbers mean nothing... especially since most drs go by the TSH and T4 only. My favorite books are by Dr. Stephen Langer, Dr. Broda Barnes, Dr. Mark Starr and Dr. Datis Kharrazian, all of which describe longtime practice of treating sx ... and going by BBT.
Blood tests do not show what is actually getting into the body's cells, nor do they show whether the cell mitochondria is actually using the hormone once it's there. And the common T4 testing doesn't show conversion to active T3, another common problem. Reverse T3 blocks the receptor but is not used by body.
ETA: That website is down right now. Hope it comes back.