My 4yr olds 6th sense

So I'm 9wks and have told a good amount of ppl I was expecting almost every one had said something about it being twins. At my 8wk internal US I made sure to ask the tech if there were two she said nope only one. And we were talking about gender and she said ask your 4 yr old the have some crazy 6th sense and are about 85% accurate. Well my son has never been specific on what it is just what he wants but last night he asked me how many babies were having I said one. He said mom stop lying were having two!