What is actually atypical autism?

I had my session on Wednesday, my therapist after talking to me again said he is more convinced I’m autistic. He also saw some of my works and my “brain massage” the notebook with 10 digit numbers and he said in his opinion I’m an atypical autistic. It’s not the final diagnosis, it’s his opinion. I couldn’t actually find much about it. I only know that atypical autism now is actually not considered autism, but communication disorder and includes lower IQ level (under 80), also that this disorder does not meet the criteria for Asperger or Kenner Syndrome. I’m not so sure why it’s atypical autism in his opinion, but I’m not gonna argue with his opinion. I think maybe because I get sometimes totally blocked and can’t speak, only communicate with pictures, that happened during the last session, maybe because of my untypical perception and strong repetitive behaviours… or because of my weird reactions- laughing in stressful situations, not showing emotions when talking about trauma etc. I couldn’t really find much about the atypical autism. Now all autism is just Autism Spectrum Disorder or Condition and the only differences used in medical records are the levels of support needed. 
mom angry at myself because during the last 3 months  I have written a lot in my diary about autism and about my life, but when the appointment came, it turned out I couldn’t say anything. I just kept repeating one word from the doctor’s question “what have you found out about Autism” and I only repeated “found out, found out” and couldn’t speak. I don’t know why it was so hard for me. I have IQ tested online on the Mensa official website, the result is 107. Not Einstein, but pretty ok. But sometimes people may think I’m under 70. The doctor also pointed that I understand everything literally and straightforward. The only thing I could actually say at the end of our appointment was about my early childhood, what I know from my parents and grandparents also my sister. The doctor asked me if I can imagine myself having this diagnosis. I told him I don’t know. It’s something unusual for me that a doctor asks me if I imagine myself having a diagnosis. Is there anything weird or I should be worried or change the therapist or is it all ok?