Help Please!

I was told I was having a girl at 16 weeks 2 days. I personally didn't see any boy bits and I have a son already. I was told he was a boy at 16 weeks 6 days. My question is .. Has anyone been told they were having a girl around 16 weeks and it changed to a boy? I've told family its a girl and now worried it might change and all the pink will be a waste 😔 my sister said its hard to tell its a girl but surely at 16 weeks if they say girl it should be as boy parts would be obvious by then (my son was)? If I could please have some feedback and opinions I would be so grateful! Starting to worry myself 😔