Early autism signs ?

Please don’t be rude to me I’m a first time mom and I’m just concerned. My daughter is going to be 8 months next month and she would sometimes flap her arms and legs , she has recently started shaking her head like saying no , I noticed she’ll open and close her left hand she responds to her name when she’s not distracted she responds to noise and she smile at people and loves interaction . I see all over the internet signs of autism and I see that she could have it am I over reaching. ?