Anatomy scan question

So today was my 20 week appointment with my OB. I was under the impression that obviously I would be getting the anatomy scan today. Well he checked for a heartbeat with the Doppler asked if I had any questions and proceeded to tell me to have a nice day. I stopped him and said that I thought I’d be getting a scan today and he said “well I can send you for one if you want one”..... long story short I had him send me to an imaging center for my anatomy scan. I wasn’t aware that i had to ask for one? Does this make sense? I’m so confused. Now I don’t know if I’ll have another scan the rest of the pregnancy. I thought anatomy scans were important, and I feel like if I didn’t ask for one I wouldn’t have gotten one at all.