Autism diagnosis

Hi everyone  how do I go about find out if I already have a diagnosis of autism? When I was a child I was in main stream school till p4 then I remembered attending an assessment then shortly afterwards I started attending a special needs primary school and a special needs secondary school but I ha e never been told why I had to attend these schools. Anytime I asked my mum her answer was you needed to go because you where slow in picking up information. Also did ask my mum if I was ever diagnosed with autism but she can't remember what the results of the assessment with the educational psychologist and speech and language therapist was. Now that I am older I would really like to know if iam autistic or not as my 2 children are autistic and have a formal diagnosis of autism.