Anti TPO antibodies dose not confirm u have graves. As it may b positive in thyroiditis as well. So confirmatory test for graves is iodene/ technetium uptake scan or
thyroid receptor stimulating antibodies (TRAB). So can continue carbimozole repeat thyroid test after 6 weeks get the above test.
Next Steps
TRAB test, Technitium uptake scan, consult endocrinologist