B12 is getting checked with gp , would thet3 and t4 affect tsh result or is that a separate test that can show up a alternative answer?

Alternative answer?: I don't understand your question. Alternative answer to what? B12 is a water soluble vitamin. Tsh is a measure of thyroid function (actually it's signal from pituitary to thyroid). T3 (liothyronine) & T4 are actual hormones produced by thyroid. These are all separate/different tests that need to be ordered individually. Not sure what you want to (dis)prove w/these tests. Please explain your symptoms to your doc.