What was ur first sign of autism?

Kh

Im just curious for anyone who has an autistic child what were some of the signs? My daughter is only 6 months n i dont think she is but it is something that i think about alot..i know most kids cant be diagnosed until they are about 2 years old but if u do have a child who was diagnosed do u look back at some of the things they did when they were babies? I know this is a sensitive subject but its just something i am genuinely curious about.