Hello and welcome – we’re fellow patients here, but in general, nodules are VERY common. They only become a problem if they are suspicious for malignancy (the vast majority are benign) or if they start overproducing thyroid hormone, which can cause symptoms of hyperthyroidism. If your insurance will cover, asking for antibodies specific to Graves’ might be helpful (TSI or TRAb). There’s also a more involved test called a radioactive iodine uptake & scan that can show how your thyroid is taking up iodine, which can also provides some clues on the cause.
Regardless of the cause, a good question for your doc would be whether they will recommend treatment now – or if they will wait to see if your T3/T4 go out of range.