Hmm, maybe it could be hormonal as your doctor said.
Thorn brought up a good point-- you may also want to do a Liver Flush right before or after your period. Your thyroid is involved with the liver.
I was told after I stopped taking my birth control cold turkey-- to go right into doing a series of 3 liver flushes. I did, and this helped my thyroid from the hormones of the birthcontrol pill to the point that I dropped 15 lbs of fat that month.