anatomy scan

So I was informed by my doctor that since my daughter has colpocephaly that the baby I'm currently pregnant with will have to have a targeted ultrasound instead of an anatomy scan. I'm not really worried about the baby having any conditions what I am upset about is that this ultrasound isn't until I'm 21 weeks. I'll find out the gender then, but I really would like to know as soon as I can. Do you ladies think I should just wait it out? Or find a place that'll do the scan earlier to learn the gender?