Potty shot 16 weeks! Help!

I've just been for a private gender scan at 16 weeks 1 day. We've been told it's a girl! She had a good look and seemed pretty confident and in comparison to my son's it's totally different. I guess I'm just in shock and worried ill get to my 20 week and it'll be a boy... any girl mums out there who can tell me what you think?! Is this a define girl shot? Thank you 😄💖