Baby #2 with older autistic sibling

My husband and I have finally decided to try for baby #2. We already have a 5 year old autistic son so we’re extremely nervous trying for a baby - hoping our son transitions okay and it doesn’t rock his world. Also I went through breast cancer two years ago so there’s a chance chemo affected my fertility. All the signs are there everything is okay (period started as soon as chemo was done and I started ovulating, double checking with ovulation sticks) but it’s still nerve racking knowing it’s a possibility.

Does anyone have any advice on trying for #2 with an autistic sibling??