I'm in the US and had an ultrasound at 6, 10, 12, 17, 22, and 28 weeks and I have at least one more at 34 weeks. Seems a little excessive since my only issue was placenta previa, which fixed itself. Don't get me wrong, I love seeing my LO but the $35 copays are getting very expensive! Every Dr is different, I think mine is extra cautious!