I also had my thyroid removed due to thyroid cancer. It's been 7 years now, so I am pretty good at feeling how my thyroid levels are when they're in the right place and when they're not, kwim? I was on 175mcg at the end of my pregnancy, and dropped to 150mcg at about 3-4 months postpartum. My TSH levels were really low, (I think in that range, maybe .3 but I can't find the actual number, sorry) and the endo. was wanting to reduce my dose mostly to prevent osteoporosis later on. She seemed to think that it would not be a problem for bfing (either way) and she seemed a least to a certain degree knowledgeable of bfing problems and thyroid problems, which was refreshing. I never had any problems with low supply (more like bordering on oversupply though I didn't know it). Of course the mcgs you take to be at the right level varies per person, but it sounds to me like the amount you would be taking is probably not going to be too far off, but maybe need some fine-tuning. But I'd recommend just keeping in touch with your endocrinologist, for sure. It takes a while for thyroid levels to adjust, so maybe getting some levels drawn a month or so in if you're worried about it once you switch back to your new dose?