Normal wait times?

My first sono I was 8 weeks out from my LMP. Turns out my scan was showing 6 weeks 2 days(I have an irregular period so I didn’t think much of this) Everything looked good so the doc said see you at week 12. Recently I was talking to some friends who said that happened to them and they were rescanned at the 8 week mark just incase. Im still over 3 weeks out now from my next scan and wondering if its normal they don’t want to see me again before the 12 week mark?