Curious 🤔

I recently underwent an anembryonic pregnancy (blighted ovum) at 9 weeks December of 2016 & also had a D&C performed in January. I am now 5 weeks and 5 days pregnancy and they are not going to do an ultrasound until I'm 10 weeks. I don't understand . Has anyone who's last pregnancy turned out to miscarriage followed by a d&c had/has to wait average time for the first ultrasound?