How likely is it that my baby will have genetic disorders?

My mother is epileptic, cerebral palsy.. shes' had seizures her entire life. I am 21 weeks pregnant and lately ive been feeling my baby "tremble" or "shiver" inside me. Ive felt hiccups, totally different sensation. It really feels like,, hes freezing cold and his muscles are shaking uncontrollably! could my son have developed this??? =(