Autistic moms help? Thinking of ttc.

Sorry I just don't really know who else to talk to. My 4 year old was diagnosed with autism when he was 2 and my husband and my parents are in denial. I noticed a difference in him since he was 1 and the doctors recommended a developmental specialist who also recommended speech therapy and occupational therapy. I took him to this specialists until he turned 3, then he went to a developmental preschool through the Albuquerque public school system. I also have a 3 year old who doesn't have any type of developmental disorders and have been thinking about another baby. My husband has 9 siblings and his sibling who is one year younger than him is also autistic non verbal and medicated and can never live alone...my husband refuses to get the blood test to see if the autism is in his DNA or whatever....I just don't know what to do. I get really scared to have another baby with autism but I've really been thinking about having another baby. Idk.