Do TSH levels increase during the menstrual cycle? When I first got my TSH tested my menstrual cycle was on and the TSH level showed up as 9.89. At the recommendation of an endocrinologist I got it retested less than a month later (at this time my menstrual cycle was not on) and this time the TSH level came back as normal at 0.83. Then again it was retested less than a month later (this again happened to be the time when my menstrual cycle was on) and the TSH came back at 6.15. I am due to meet the endocrinologist again. I am a little worried about my fluctuating TSH level. My monthly cycles do vary over a 35-40 day cycle but that apart I do not seem to have any other symptoms of high TSH levels. Could diet or exercise affect TSH levels? I have not been on any medication all this time except for some prenatal vitamins and anxious to get pregnant. Can someone please advise what may be causing the fluctuating levels in less than 2 months time when I am not taking any medication?