Have you ever thought your child might be autistic but turns out they were not?

Just wondering what the major red flags are?

My son when really excited flaps his arms. He doesn’t always respond to his name especially when a movie is on so I can’t tell there.

But he’s very outgoing, very empathetic and very social with other kids. He’s got his favorite scenes in movies and stuff that he just loves to laugh at. When he plays with his toy cars by himself he is now making “vroom vroom” sounds to mimic cars. Personally I don’t think he’s autistic. I think my wife and her mom are tripping balls! (I’m not saying being autistic is bad but from what I’ve read I just don’t believe him to be but you tell me what you think, also how can we get this medically checked?)

My son is officially 16 months by the way.