1st ultrasound at 18 weeks?

I got my ultrasound date come in the mail today. I’m 7 weeks now (or at least according to this app). My dr said I’m suppose to get one at 8-9 weeks for a dating scan then another at 18-20 weeks for an anatomy scan. Anyways, my 2st ultrasound would be in sept. I will be 18 weeks by then. Is this normal? This is my second pregnancy but with my first I got one at 12 weeks then again at 18. I’m also a t1 diabetic mom. Has anyone else got their first ultrasound while being this late?