It's thought that in the beginning sometimes the thyroid will swell to catch all the Iodine now coming in, then will calm down. I'm not sure of a time frame for the swelling to go down. Maybe a month or so? To help your thyroid catch up, raise how much Iodine you're taking when you can. Your goal is at least 100 mg. If you don't tolerate that well, put it in orange juice or Vitamin C solution. Selenomethionine 200 mcg is important for thyroid support, and plenty of magnesium is a good all-round supplement. Vitamin C, at least 3000 mg a day, will also help your progress.