nicknames

Ok, so I am 33 weeks and 1 day with my first....we are having a baby boy and my fiancé, being the absolutely amazingly perfect man he is, insisted that we name our son after my father because he knew how much it would mean too me...and he's always liked the name Thomas anyways....so our son will be Thomas Lawrence 2nd....I keep calling him baby Thomas and the other day my mother says "you have to stop calling him Thomas it sounds so old, you should call him Tommy or something...." honestly I haven't even started to think about nicknames yet as he hasn't even arrived, and generally you give a nickname once you have the baby and it comes naturally....but at the same time I really don't like Tommy at all....idk any opinions?!?!