No internals are completely unneccessary unless there is a reason like to obtain your progress in labour or to see if your cervix is open enough to allow your membranes to be broken in the event of an induction. Actually unless your thought to be in strong labour they don't like them done at all before 37weeks because of the risk of starting something or exacerbating something thats already going on (not that thats a concern for you as your 39weeks). Id say yeah for you and hope you don't need many (your usally very lucky to avoid them during labour though).