Good Afternoon. I Am An Active Athletic 41 Year Old

Good afternoon. I am an active athletic 41 year old female. I'm 5"11 and 200lbs. My question is I workout about 3-5 times per week, I eat clean 90 percent of the time, however, I am gaining weight. I don't want to get a standard thyroid test as those are not accurate. I did some research, and think I may be lacking in my iodine levels. Thoughts