can you ask your care provider for their opinion? that may help sway him - if all is going well etc etc they wont have a prob with it...
i think it is v important to do what suits you at the time, depending on how you feel. i worked up to 38 wks (DS was born at 39 wks) and this was right for me, i am not the type to be at home and i would have been working myself up with all the 'what ifs' if i had time on my hands.. others feel differently. that said, i think i will finish a bit earlier this time around...