The pregnancy should not be effected by thyroid surgery and levothyroxine replacement which would follow thyroid gland removal. Would need to make sure levels are appropriate before trying to conceive. This is a common scenario. The main question is indication for thyroid surgery -- ie, suspicious biopsy, compressive symptoms, thyroid nodule over-activity....would make sure there is a clear indication before removing the thyroid.
My second baby is 1 week old, after total thyroidectomy cause of graves. He is perfectly healthy and pregnancy was just fine. all the best!