Dye test

So I met with a fertility doctor today for the first time. I'm military so I had to see a Navy doctor. He has ordered a dye ultra sound to be done following my next period and did the blood panel. He said if he doesn't find anything in the ultrasound then he ll start me on Clomid and once the follicle I'd mature and healthy will follow w iui. My first concern is the dye test...is it painful and to what extent? Secondly he's checking for a septum bc I ve had recurrent miscarriages and I rarely hear of that being a reason so I'd like to hear your thoughts on that. I'm very excited to finally be seeing a fertility specialist as I've experienced much resistance from triage on the matter. I ve wanted this for so long but now it's here and I find I am much more nervous for the outcome than I anticipated.