I was diagnosed with an underactive thyroid 25 yrs ago after having pituartary problems for 5 years. All been fine taking 125mcg tyroxine, until I became pregnant 10 yrs ago and was increased to 225mcg and have been on this dose ever since. In April this yr I started to feel odd so got my thyroid checked and it was really high moved down to 100mcg and feel better but have put on a stone since I've gone to lower dosag. I'm walking min 3 miles a day and not over eating - my last blood test showed I was in correct levels. Any advice please.