Maybe they're trying to put your blood pressure up by upsetting you, so they've got an excuse not to birth your baby at home!
Anyway - ditto what everyone else says about being assertive.
I strongly recommend the 'broken record' technique with negative health professionals (as pinched from Nicky Wesson's 'Homebirth' book)
HP: "If your waters go and you don't go into labour within 24 hours you'll have to come in and be induced you know"
Mum: I intend to have my baby at home, but thankyou for your advice - I'll be sure to consider it.
HP: "And you do realise that if there isn't a midwife free you'll have to come in and have your baby on the labour ward"
Mum: I intend to have my baby at home. I appreciate that staffing may be difficult so it's good you have a lot of notice so that you can make sure that properly qualified cover is available.
etc etc
You get the picture
"Surely you have a right to have your baby at home if that's what you want (and assuming an untroubled, uncomplicated pregnancy)?"
Actually you have a right to have your baby at home, full stop. I say that as someone who had a planned homebirth after a pregnancy that wasn't 'untroubled' or 'uncomplicated'.