Are there early signs of autism in a 1.5 yo?

What are the early signs? My son still isn’t speaking real words but he can point to stuff he wants me to see, can understand and follow basic directions, has eye contact. Is it genetic? He doesn’t seem to have any other symptoms except the speech issue and he does flap his hands but it’s usually only when we tell him to say hello or bye, occasionally he’ll do it when he’s very excited but not often. He recently started standing on his tippy toes but it’s not all the time, just sometimes. I’m worried and stressed all the time about it, I just want to do things right, it’s just so hard because I feel like a lot of this is just him learning new things but idk