Follow-up sonogram??

We just went for anatomy scan yesterday and found out we are having another lil boy💙 But they called me today to do a follow up scan to get .ore images. Is this normal?? The lady who scheduled the apt said that sometimes they need better pics or the baby may have been positioned wrong. It seemed like she got everything yesterday, and was very positive.. Im waiting for the dr to call me back, i called her to ask about the reason for it. Im just very worried😕