Parents of children with autism: what was happening before you noticed regression?

My 13 month old started developing fevers, crying and whining more, throwing absolute fits with high pitched screaming, not sleeping, vomited 5 times, has had awful diarrhea and has lost some of her words. She had her MMR, pneumonia and chicken pox vaccine last week when this all started. (I am NOT anti-vaccines, I am just mentioned this as the start of when I noticed her change in behavior). The pediatrician said some babies have a reaction like this to MMR and not to worry, but I only see low grade fevers and overall crankiness as side effects. The rest of the symptoms are reported on sites that have accounts of regression into autism. My daughter was already showing signs of sensory process disorder. Just wondering if this could be the road we’re heading down?