That sounds normal, Casie. Your doctor probably expects that it will be at least six weeks before the extra thyroid hormone from your damaged gland will start to leave your system enough that a blood test can monitor any changes.
My doctor told me it would be 6-8 weeks before I started to feel better, and 2-3 months before I went hypo. (It was three months for me.) How long it takes depends on the dose you received (whether it was ablative or meant to leave you with partial thyroid function left), and how your body reacts to it. Some people have to have more than one RAI to do the job.
Didn’t your doctor give you some idea what to expect? If not, I suggest you call and ask questions. I write mine down before phone calls or appointments so I don’t waste the doctor’s time, but still don’t forget anything I wanted to ask.
I hope it goes well for you.
Dianne W