I had norovirus when I was 6 months pregnant with ds2, was given anti-sickness meds bc I couldn't even keep water down. I had a gp home visit for that, she was so worried that the stress on my body would start premature labour. I was very sick, but I didn't have paracetamol. My son has dyspraxia, and probably autism too (but not diagnosed).
We already have autism on both sides of the family, of course those uncles and aunts were never diagnosed back in the 70s bc people just didn't back then. You were simply thought of as "odd".
I highly doubt that paracetamol gives unborn babies autism, if anything, its far more likely the illness and fever that the mother is trying to treat causes stress to the baby who already has a predisposition to autism. Maybe!... but Autism has always existed, there isn't an 'explosion' in cases, were just better at spotting it now.
Think back to the Victorian age, with all those collectors who founded museums and spent their life cataloguing, and bachelor men who had obsessions with rules and order. Sherlock Holmes! High-functioning Autism was celebrated back then. It certainly hasn't just appeared in recent history, and it's bugger-all to do with paracetamol!