A GP can't force you to do anything you don't want. If you don't agree with them and they make an issue of it, get another GP.

I do know Womens ultrasound Malvern has some very experienced doctors attached, so that may be why they're more expensive. Their equipment may be better too. I don't know - ask your GP why he/she is insisting. $100 is a big difference, especially given the medicare rebate is the same, no matter who you go with.

On a separate note, re: upsetting the GP. Remember they are a care provider, ie, suppliers. You are the customer. It is their job to SERVE you to the best of their ability. If you don't get along, it may be better to find another doctor. Just as, if they think they're offering advice you're ignoring, they can choose not to serve you. However, they should give a reasonable explanation, not just throw their weight around. There's plenty more GP's out there, after all. Sorry for getting on my high horse, but the whole "do what I say cos I'm a doctor" mentality really does my head in If you feel bullied or patronised, find someone else.