mono/di echo ultrasound

I need some help from my mono/di parents whether your expecting now or have mono/di twins. I'm 25weeks pregnant currently and I just moved from nj to nv and my nj dr was very persistent about getting an echo ultrasound now I'm in nv and they seem to be taking their time about ordering an echo ultrasound. My question is did any or all of you get an echo ultrasound to make sure their heart were producing properly and when did you have them?